639957900 has 72 divisors (see below), whose sum is σ = 1858881024. Its totient is φ = 169985600.

The previous prime is 639957887. The next prime is 639957947. The reversal of 639957900 is 9759936.

It is a happy number.

639957900 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×639957900² = 819092227544820000, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 639957900.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 74845 + ... + 82955.

It is an arithmetic number, because the mean of its divisors is an integer number (25817792).

Almost surely, 2^639957900 is an apocalyptic number.

639957900 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639957900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (929440512).

639957900 is an abundant number, since it is smaller than the sum of its proper divisors (1218923124).

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

639957900 is a wasteful number, since it uses less digits than its factorization.

639957900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8391 (or 8384 counting only the distinct ones).

The product of its (nonzero) digits is 459270, while the sum is 48.

The square root of 639957900 is about 25297.3891933535. The cubic root of 639957900 is about 861.7549794108.

The spelling of 639957900 in words is "six hundred thirty-nine million, nine hundred fifty-seven thousand, nine hundred".