639997567776 has 72 divisors (see below), whose sum is σ = 2079992101824. Its totient is φ = 182856447360.

The previous prime is 639997567739. The next prime is 639997567787. The reversal of 639997567776 is 677765799936.

639997567776 is a `hidden beast` number, since 6 + 399 + 97 + 5 + 6 + 77 + 76 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

It is a junction number, because it is equal to n+sod(n) for n = 639997567695 and 639997567704.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 158727540 + ... + 158731571.

It is an arithmetic number, because the mean of its divisors is an integer number (28888779192).

Almost surely, 2^639997567776 is an apocalyptic number.

It is an amenable number.

639997567776 is an abundant number, since it is smaller than the sum of its proper divisors (1439994534048).

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

639997567776 is a wasteful number, since it uses less digits than its factorization.

639997567776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 317459134 (or 317459123 counting only the distinct ones).

The product of its digits is 5671065960, while the sum is 81.

The spelling of 639997567776 in words is "six hundred thirty-nine billion, nine hundred ninety-seven million, five hundred sixty-seven thousand, seven hundred seventy-six".