639433248256 has 160 divisors (see below), whose sum is σ = 1451501669376. Its totient is φ = 278777856000.

The previous prime is 639433248239. The next prime is 639433248269. The reversal of 639433248256 is 652842334936.

It is a junction number, because it is equal to n+sod(n) for n = 639433248197 and 639433248206.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 19712691 + ... + 19745101.

Almost surely, 2^639433248256 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639433248256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (725750834688).

639433248256 is an abundant number, since it is smaller than the sum of its proper divisors (812068421120).

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

639433248256 is a wasteful number, since it uses less digits than its factorization.

639433248256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32584 (or 32568 counting only the distinct ones).

The product of its digits is 22394880, while the sum is 55.

The spelling of 639433248256 in words is "six hundred thirty-nine billion, four hundred thirty-three million, two hundred forty-eight thousand, two hundred fifty-six".