639418564428 has 96 divisors (see below), whose sum is σ = 1752542830080. Its totient is φ = 177676899840.

The previous prime is 639418564397. The next prime is 639418564453. The reversal of 639418564428 is 824465814936.

It is a happy number.

It is a super-2 number, since 2×639418564428² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 245026 + ... + 1157097.

It is an arithmetic number, because the mean of its divisors is an integer number (18255654480).

Almost surely, 2^639418564428 is an apocalyptic number.

It is an amenable number.

639418564428 is an abundant number, since it is smaller than the sum of its proper divisors (1113124265652).

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

639418564428 is a wasteful number, since it uses less digits than its factorization.

639418564428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1402287 (or 1402285 counting only the distinct ones).

The product of its digits is 39813120, while the sum is 60.

The spelling of 639418564428 in words is "six hundred thirty-nine billion, four hundred eighteen million, five hundred sixty-four thousand, four hundred twenty-eight".