639399993936 has 160 divisors (see below), whose sum is σ = 1860710240256. Its totient is φ = 187443072000.

The previous prime is 639399993913. The next prime is 639399993949.

639399993936 is nontrivially palindromic in base 10.

It is a congruent number.

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, 70328751 + ... + 70337841.

Almost surely, 2^639399993936 is an apocalyptic number.

639399993936 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639399993936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (930355120128).

639399993936 is an abundant number, since it is smaller than the sum of its proper divisors (1221310246320).

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

639399993936 is a wasteful number, since it uses less digits than its factorization.

639399993936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13441 (or 13435 counting only the distinct ones).

The product of its digits is 1549681956, while the sum is 78.

The spelling of 639399993936 in words is "six hundred thirty-nine billion, three hundred ninety-nine million, nine hundred ninety-three thousand, nine hundred thirty-six".