639765252 has 36 divisors (see below), whose sum is σ = 1848211456. Its totient is φ = 182790000.

The previous prime is 639765251. The next prime is 639765257. The reversal of 639765252 is 252567936.

639765252 is a `hidden beast` number, since 6 + 397 + 6 + 5 + 252 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a junction number, because it is equal to n+sod(n) for n = 639765198 and 639765207.

It is not an unprimeable number, because it can be changed into a prime (639765251) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1269124 + ... + 1269627.

Almost surely, 2^639765252 is an apocalyptic number.

It is an amenable number.

639765252 is an abundant number, since it is smaller than the sum of its proper divisors (1208446204).

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

639765252 is a wasteful number, since it uses less digits than its factorization.

639765252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2538768 (or 2538763 counting only the distinct ones).

The product of its digits is 680400, while the sum is 45.

The square root of 639765252 is about 25293.5812410975. The cubic root of 639765252 is about 861.6684987039.

The spelling of 639765252 in words is "six hundred thirty-nine million, seven hundred sixty-five thousand, two hundred fifty-two".