639372860 has 192 divisors, whose sum is σ = 1706987520. Its totient is φ = 196331520.

The previous prime is 639372859. The next prime is 639372863. The reversal of 639372860 is 68273936.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639372863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3828497 + ... + 3828663.

It is an arithmetic number, because the mean of its divisors is an integer number (8890560).

Almost surely, 2^639372860 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639372860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (853493760).

639372860 is an abundant number, since it is smaller than the sum of its proper divisors (1067614660).

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

639372860 is a wasteful number, since it uses less digits than its factorization.

639372860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276 (or 274 counting only the distinct ones).

The product of its (nonzero) digits is 326592, while the sum is 44.

The square root of 639372860 is about 25285.8233008142. The cubic root of 639372860 is about 861.4922981503.

The spelling of 639372860 in words is "six hundred thirty-nine million, three hundred seventy-two thousand, eight hundred sixty".