639957901 has 8 divisors (see below), whose sum is σ = 699282144. Its totient is φ = 580824720.

The previous prime is 639957887. The next prime is 639957947. The reversal of 639957901 is 109759936.

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 639957901 - 2⁹ = 639957389 is a prime.

It is a super-2 number, since 2×639957901² = 819092230104651602, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639957001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40711 + ... + 54196.

It is an arithmetic number, because the mean of its divisors is an integer number (87410268).

Almost surely, 2^639957901 is an apocalyptic number.

It is an amenable number.

639957901 is a deficient number, since it is larger than the sum of its proper divisors (59324243).

639957901 is a wasteful number, since it uses less digits than its factorization.

639957901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95531.

The product of its (nonzero) digits is 459270, while the sum is 49.

The square root of 639957901 is about 25297.3892131184. The cubic root of 639957901 is about 861.7549798597.

The spelling of 639957901 in words is "six hundred thirty-nine million, nine hundred fifty-seven thousand, nine hundred one".