639575881 has 24 divisors (see below), whose sum is σ = 787377024. Its totient is φ = 516922560.

The previous prime is 639575879. The next prime is 639575897. The reversal of 639575881 is 188575936.

639575881 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 639575881 - 2¹ = 639575879 is a prime.

It is a super-2 number, since 2×639575881² = 818114615113852322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (639575801) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 76021 + ... + 84013.

It is an arithmetic number, because the mean of its divisors is an integer number (32807376).

Almost surely, 2^639575881 is an apocalyptic number.

It is an amenable number.

639575881 is a deficient number, since it is larger than the sum of its proper divisors (147801143).

639575881 is a wasteful number, since it uses less digits than its factorization.

639575881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8101 (or 8094 counting only the distinct ones).

The product of its digits is 1814400, while the sum is 52.

The square root of 639575881 is about 25289.8375044206. The cubic root of 639575881 is about 861.5834721376.

The spelling of 639575881 in words is "six hundred thirty-nine million, five hundred seventy-five thousand, eight hundred eighty-one".