639778877936 has 40 divisors (see below), whose sum is σ = 1365648650928. Its totient is φ = 287929280000.

The previous prime is 639778877923. The next prime is 639778877953.

639778877936 is nontrivially palindromic in base 10.

It is a congruent number.

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, 17977805 + ... + 18013356.

Almost surely, 2^639778877936 is an apocalyptic number.

It is an amenable number.

639778877936 is an abundant number, since it is smaller than the sum of its proper divisors (725869772992).

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

639778877936 is a wasteful number, since it uses less digits than its factorization.

639778877936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35991281 (or 35991275 counting only the distinct ones).

The product of its digits is 4032758016, while the sum is 80.

The spelling of 639778877936 in words is "six hundred thirty-nine billion, seven hundred seventy-eight million, eight hundred seventy-seven thousand, nine hundred thirty-six".