639535131 has 12 divisors (see below), whose sum is σ = 932920560. Its totient is φ = 422134800.

The previous prime is 639535123. The next prime is 639535133. The reversal of 639535131 is 131535936.

639535131 is a `hidden beast` number, since 639 + 5 + 3 + 5 + 13 + 1 = 666.

It is not a de Polignac number, because 639535131 - 2³ = 639535123 is a prime.

It is a super-2 number, since 2×639535131² = 818010367566374322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (639535133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 350871 + ... + 352688.

It is an arithmetic number, because the mean of its divisors is an integer number (77743380).

Almost surely, 2^639535131 is an apocalyptic number.

639535131 is a deficient number, since it is larger than the sum of its proper divisors (293385429).

639535131 is a wasteful number, since it uses less digits than its factorization.

639535131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 703666 (or 703663 counting only the distinct ones).

The product of its digits is 36450, while the sum is 36.

The square root of 639535131 is about 25289.0318320018. The cubic root of 639535131 is about 861.5651734112.

The spelling of 639535131 in words is "six hundred thirty-nine million, five hundred thirty-five thousand, one hundred thirty-one".