Base | Representation |
---|---|
bin | 100110001001000… |
… | …110101011100111 |
3 | 1122121010100102000 |
4 | 212021012223213 |
5 | 2302304431441 |
6 | 143255420343 |
7 | 21600144342 |
oct | 4611065347 |
9 | 1577110360 |
10 | 639920871 |
11 | 2a9245027 |
12 | 15a3846b3 |
13 | a2765405 |
14 | 60db9459 |
15 | 3b2a62b6 |
hex | 26246ae7 |
639920871 has 16 divisors (see below), whose sum is σ = 950730720. Its totient is φ = 425399040.
The previous prime is 639920867. The next prime is 639920891. The reversal of 639920871 is 178029936.
639920871 is a `hidden beast` number, since 639 + 9 + 2 + 0 + 8 + 7 + 1 = 666.
639920871 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.
It is not a de Polignac number, because 639920871 - 22 = 639920867 is a prime.
It is a super-2 number, since 2×6399208712 = 818997442282797282, which contains 22 as substring.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (639920821) by changing a digit.
It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24040 + ... + 43101.
It is an arithmetic number, because the mean of its divisors is an integer number (59420670).
Almost surely, 2639920871 is an apocalyptic number.
639920871 is a deficient number, since it is larger than the sum of its proper divisors (310809849).
639920871 is a wasteful number, since it uses less digits than its factorization.
639920871 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 67503 (or 67497 counting only the distinct ones).
The product of its (nonzero) digits is 163296, while the sum is 45.
The square root of 639920871 is about 25296.6573088224. The cubic root of 639920871 is about 861.7383582442.
The spelling of 639920871 in words is "six hundred thirty-nine million, nine hundred twenty thousand, eight hundred seventy-one".
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