639388877 has 8 divisors (see below), whose sum is σ = 651530880. Its totient is φ = 627361200.

The previous prime is 639388859. The next prime is 639388889. The reversal of 639388877 is 778883936.

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 639388877 - 2⁸ = 639388621 is a prime.

It is a super-2 number, since 2×639388877² = 817636272062642258, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639388807) 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, 17249 + ... + 39702.

It is an arithmetic number, because the mean of its divisors is an integer number (81441360).

Almost surely, 2^639388877 is an apocalyptic number.

It is an amenable number.

639388877 is a deficient number, since it is larger than the sum of its proper divisors (12142003).

639388877 is a wasteful number, since it uses less digits than its factorization.

639388877 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57163.

The product of its digits is 12192768, while the sum is 59.

The square root of 639388877 is about 25286.1400178042. The cubic root of 639388877 is about 861.4994918698.

The spelling of 639388877 in words is "six hundred thirty-nine million, three hundred eighty-eight thousand, eight hundred seventy-seven".