13638925640 has 32 divisors (see below), whose sum is σ = 30693385080. Its totient is φ = 5454538752.

The previous prime is 13638925627. The next prime is 13638925693. The reversal of 13638925640 is 4652983631.

It can be written as a sum of positive squares in 4 ways, for example, as 13571784004 + 67141636 = 116498^2 + 8194^2 .

It is a super-2 number, since 2×13638925640² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 203192 + ... + 261848.

Almost surely, 2^13638925640 is an apocalyptic number.

13638925640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13638925640 is an abundant number, since it is smaller than the sum of its proper divisors (17054459440).

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

13638925640 is a wasteful number, since it uses less digits than its factorization.

13638925640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64481 (or 64477 counting only the distinct ones).

The product of its (nonzero) digits is 933120, while the sum is 47.

The spelling of 13638925640 in words is "thirteen billion, six hundred thirty-eight million, nine hundred twenty-five thousand, six hundred forty".