639457912731 has 16 divisors (see below), whose sum is σ = 930224711808. Its totient is φ = 387506870400.

The previous prime is 639457912721. The next prime is 639457912741. The reversal of 639457912731 is 137219754936.

It is an interprime number because it is at equal distance from previous prime (639457912721) and next prime (639457912741).

It is not a de Polignac number, because 639457912731 - 2¹³ = 639457904539 is a prime.

It is a super-2 number, since 2×639457912731² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (639457912711) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 783966 + ... + 1376051.

It is an arithmetic number, because the mean of its divisors is an integer number (58139044488).

Almost surely, 2^639457912731 is an apocalyptic number.

639457912731 is a deficient number, since it is larger than the sum of its proper divisors (290766799077).

639457912731 is a wasteful number, since it uses less digits than its factorization.

639457912731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2169002.

The product of its digits is 8573040, while the sum is 57.

The spelling of 639457912731 in words is "six hundred thirty-nine billion, four hundred fifty-seven million, nine hundred twelve thousand, seven hundred thirty-one".