639772368 has 20 divisors (see below), whose sum is σ = 1652745408. Its totient is φ = 213257440.

The previous prime is 639772349. The next prime is 639772379. The reversal of 639772368 is 863277936.

639772368 is nontrivially palindromic in base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 639772368.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 6664248 + ... + 6664343.

Almost surely, 2^639772368 is an apocalyptic number.

It is an amenable number.

639772368 is an abundant number, since it is smaller than the sum of its proper divisors (1012973040).

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

639772368 is a wasteful number, since it uses less digits than its factorization.

639772368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13328602 (or 13328596 counting only the distinct ones).

The product of its digits is 2286144, while the sum is 51.

The square root of 639772368 is about 25293.7219088058. The cubic root of 639772368 is about 861.6716934227.

The spelling of 639772368 in words is "six hundred thirty-nine million, seven hundred seventy-two thousand, three hundred sixty-eight".