A number 
is called uban if its name (in English)
does not contain the letter "u".
In particular, it cannot contain the terms "four", "hundred", and "thousand", So the uban number following 99 is 1000000.
Despite being quite sparse, the sum of the reciprocals of uban numbers slowly diverges.
Uban numbers belong to the same family of aban numbers, eban numbers, iban numbers, and oban numbers. All quite boring, if I may speak my mind...
As for the above sets, the definition is not really precise, since large numbers may have non-standard names.
The first uban numbers are 1, 2, 3, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15, 16, 17, 18, 19, 20, 21, 22, 23, 25 more terms
Pictorial representation of remainders (mod 2, 3, ...,11) frequency. For a table of values and more details click here
A graph displaying how many uban numbers are multiples of the primes p from 2 to 71. In black the ideal line 1/p.
Uban numbers can also be... (you may click on names or numbers and on + to get more values)
a-pointer
11
13
2000093
+
9099000089
ABA
18
32
50
+
8056098000000
aban
10
11
12
+
1000000000000
abundant
12
18
20
+
50000000
Achilles
72
2000000
5000000
+
50000000000000
admirable
12
20
30
+
99000042
alt.fact.
19
alternating
10
12
16
+
98
amenable
12
13
16
+
1000000000
arithmetic
11
13
15
+
9000099
astonishing
15
27
automorphic
25
76
balanced p.
53
1000099
6000047
+
9099000013
Bell
15
52
bemirp
1088016000011
1088019000011
16068066000061
19098099000091
betrothed
48
75
binomial
10
15
20
+
8088059000035
brilliant
10
15
21
+
89000071
c.decagonal
11
31
61
+
81052016000051
c.heptagonal
22
43
71
+
56000098000043
c.nonagonal
10
28
55
+
98000077000015
c.octagonal
25
49
81
+
98010099000025
c.pentagonal
16
31
51
+
90000075000016
c.square
13
25
41
+
98000098000025
c.triangular
10
19
31
+
96000060000010
cake
15
26
42
93
Carol
47
Catalan
42
Chen
11
13
17
+
98000059
congruent
13
15
20
+
9000095
constructible
10
12
15
+
96
cube
27
1000000
8000000
+
27000000000000
Cullen
25
65
Cunningham
10
15
17
+
98010099000026
Curzon
18
21
26
+
99000090
cyclic
11
13
15
+
9000097
D-number
15
21
33
+
7000041
d-powerful
43
63
89
de Polignac
1000061
1000099
2000039
+
99000077
decagonal
10
27
52
+
36000087000052
deceptive
91
17000017
41000041
+
41000000041
deficient
10
11
13
+
9000099
dig.balanced
10
11
12
+
69000020
double fact.
15
48
droll
72
Duffinian
16
21
25
+
9000099
eban
30
32
36
+
66066066000066
economical
10
11
13
+
20000000
emirp
13
17
31
+
99000037
emirpimes
15
26
39
+
99000089
enlightened
25000000
25000000000
equidigital
10
11
13
+
19000099
eRAP
20
98
8066000045
esthetic
10
12
21
+
98
Eulerian
11
26
57
66
evil
10
12
15
+
1000000001
fibodiv
19
28
47
+
75
Fibonacci
13
21
55
89
Friedman
25
frugal
1000000
2000000
2000033
+
98000000
gapful
1000000
1000005
1000008
+
99099000099
Gilda
29
49
78
Giuga
30
good prime
11
17
29
+
93000097
happy
10
13
19
+
10000000
harmonic
28
Harshad
10
12
18
+
10000000000
heptagonal
18
55
81
+
90000081000018
hex
19
37
61
+
75000075000019
hexagonal
15
28
45
+
98000077000015
highly composite
12
36
48
60
hoax
22
58
85
+
99000083
Hogben
13
21
31
+
96040049000007
Honaker
17000077
26000069
37000097
+
77000081
house
32
78
hungry
17
hyperperfect
21
28
iban
10
11
12
+
77
iccanobiF
13
39
idoneal
10
12
13
+
93
impolite
16
32
inconsummate
62
63
65
+
95
interprime
12
15
18
+
99000090
Jacobsthal
11
21
43
85
Jordan-Polya
12
16
32
+
96
junction
1000001
1000003
1000005
+
99000070
Kaprekar
45
55
99
50000005000000
katadrome
10
20
21
+
98
Kynea
23
79
Lehmer
15
51
85
+
21025000099
Leyland
17
32
57
20000000000
lonely
23
53
Lucas
11
18
29
+
76
lucky
13
15
21
+
9000079
Lynch-Bell
12
15
36
48
m-pointer
23
61
magic
15
65
magnanimous
11
12
16
+
98
metadrome
12
13
15
+
89
modest
13
19
23
+
1000000099
Moran
18
21
27
+
96000039
Motzkin
21
51
nialpdrome
10
11
20
+
99000000000000
nonagonal
46
75
5040039000075
+
56000046000009
nude
11
12
15
+
99
O'Halloran
12
20
36
60
oban
10
11
12
+
99
octagonal
21
40
65
+
78030051000008
odious
11
13
16
+
1000000000
Ormiston
37000079
37000097
58000013
+
1063000097
palindromic
11
22
33
+
99000099000099
palprime
11
19000000091
32000000023
+
9000007000009
pancake
11
16
22
+
98000091000022
panconsummate
10
11
12
+
91
pandigital
11
15
19
+
69000020
partition
11
15
22
+
77
pentagonal
12
22
35
+
96000092000022
perfect
28
pernicious
10
11
12
+
9000093
Perrin
10
12
17
+
90
Pierpont
13
17
19
+
97
plaindrome
11
12
13
+
99
Poulet
17002089000001
power
16
25
27
+
49098049000000
powerful
16
25
27
+
99099040000000
practical
12
16
18
+
10000000
prim.abundant
12
18
20
+
99000042
prime
11
13
17
+
1000000000039
primeval
13
37
primorial
30
pronic
12
20
30
+
96040049000006
Proth
13
17
25
+
57031000065
pseudoperfect
12
18
20
+
1000000
rare
65
repdigit
11
22
33
+
99
repfigit
19
28
47
+
75
repunit
13
15
21
+
96040049000007
Ruth-Aaron
15
16
25
+
78
Saint-Exupery
60
60000000
2040000000
+
83086080000000
self
20
31
42
+
1000000087
self-describing
22
semiprime
10
15
21
+
99000097
sliding
11
20
25
+
70000000000000
Smith
22
27
58
+
99000083
Sophie Germain
11
23
29
+
9096000029
sphenic
30
42
66
+
99000098
square
16
25
36
+
98010099000025
star
13
37
73
+
96000072000013
strobogrammatic
11
69
88
+
99000096000066
strong prime
11
17
29
+
99000023
super Niven
10
12
20
+
48048000000
super-d
19
31
69
+
9000081
superabundant
12
36
48
60
tau
12
18
36
+
1000000000
taxicab
27000008
1027000000
6013000000
+
98027053000000
tetrahedral
10
20
35
56
tetranacci
15
29
56
triangular
10
15
21
+
98000091000021
tribonacci
13
81
trimorphic
25
49
51
+
50000000000001
truncatable prime
13
17
23
+
97
twin
11
13
17
+
97000021
Ulam
11
13
16
+
10000087
unprimeable
1000010
1000012
1000015
+
10000000
untouchable
52
88
96
upside-down
19
28
37
+
91
wasteful
12
18
20
+
9000099
weak prime
13
19
23
+
99000079
weakly prime
13075000087
72047000057
95053000019
96053000053
weird
70
Woodall
17
23
63
80
Zuckerman
11
12
15
36
Zumkeller
12
20
28
+
96
zygodrome
11
22
33
+
99000099000099