639714857 has 8 divisors (see below), whose sum is σ = 696604800. Its totient is φ = 585147024.

The previous prime is 639714851. The next prime is 639714917. The reversal of 639714857 is 758417936.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 639714857 - 2⁸ = 639714601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (639714851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 579953 + ... + 581054.

It is an arithmetic number, because the mean of its divisors is an integer number (87075600).

Almost surely, 2^639714857 is an apocalyptic number.

It is an amenable number.

639714857 is a deficient number, since it is larger than the sum of its proper divisors (56889943).

639714857 is a wasteful number, since it uses less digits than its factorization.

639714857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1161055.

The product of its digits is 1270080, while the sum is 50.

The square root of 639714857 is about 25292.5850201200. The cubic root of 639714857 is about 861.6458732570.

The spelling of 639714857 in words is "six hundred thirty-nine million, seven hundred fourteen thousand, eight hundred fifty-seven".