639577020 has 48 divisors (see below), whose sum is σ = 1852572960. Its totient is φ = 164672256.

The previous prime is 639576997. The next prime is 639577033. The reversal of 639577020 is 20775936.

It is a self number, because there is not a number n which added to its sum of digits gives 639577020.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 182047 + ... + 185526.

It is an arithmetic number, because the mean of its divisors is an integer number (38595270).

Almost surely, 2^639577020 is an apocalyptic number.

639577020 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

639577020 is an abundant number, since it is smaller than the sum of its proper divisors (1212995940).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

639577020 is a wasteful number, since it uses less digits than its factorization.

639577020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 367614 (or 367612 counting only the distinct ones).

The product of its (nonzero) digits is 79380, while the sum is 39.

The square root of 639577020 is about 25289.8600233374. The cubic root of 639577020 is about 861.5839835927.

The spelling of 639577020 in words is "six hundred thirty-nine million, five hundred seventy-seven thousand, twenty".