639757939394 has 16 divisors (see below), whose sum is σ = 1097014864128. Its totient is φ = 274110232032.

The previous prime is 639757939361. The next prime is 639757939451. The reversal of 639757939394 is 493939757936.

It is a Curzon 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 7 ways as a sum of consecutive naturals, for example, 5923067 + ... + 6030110.

It is an arithmetic number, because the mean of its divisors is an integer number (68563429008).

Almost surely, 2^639757939394 is an apocalyptic number.

639757939394 is a deficient number, since it is larger than the sum of its proper divisors (457256924734).

639757939394 is a wasteful number, since it uses less digits than its factorization.

639757939394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11957009.

The product of its digits is 1041624360, while the sum is 74.

The spelling of 639757939394 in words is "six hundred thirty-nine billion, seven hundred fifty-seven million, nine hundred thirty-nine thousand, three hundred ninety-four".