[go: up one dir, main page]

Search a number
-
+
31213240 = 2351097159
BaseRepresentation
bin111011100010…
…0011010111000
32011201210111221
41313010122320
530442310430
63033001424
7526210462
oct167043270
964653457
1031213240
1116689a73
12a553274
13660b296
144207132
152b1857a
hex1dc46b8

31213240 has 32 divisors (see below), whose sum is σ = 70884000. Its totient is φ = 12369024.

The previous prime is 31213213. The next prime is 31213243. The reversal of 31213240 is 4231213.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31213243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 781 + ... + 7939.

It is an arithmetic number, because the mean of its divisors is an integer number (2215125).

Almost surely, 231213240 is an apocalyptic number.

It is an amenable number.

31213240 is an abundant number, since it is smaller than the sum of its proper divisors (39670760).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31213240 is a wasteful number, since it uses less digits than its factorization.

31213240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7279 (or 7275 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 31213240 is about 5586.8810619164. The cubic root of 31213240 is about 314.8567081538.

Adding to 31213240 its reverse (4231213), we get a palindrome (35444453).

The spelling of 31213240 in words is "thirty-one million, two hundred thirteen thousand, two hundred forty".

Divisors: 1 2 4 5 8 10 20 40 109 218 436 545 872 1090 2180 4360 7159 14318 28636 35795 57272 71590 143180 286360 780331 1560662 3121324 3901655 6242648 7803310 15606620 31213240