639099968400 has 480 divisors, whose sum is σ = 2295375408000. Its totient is φ = 168887255040.

The previous prime is 639099968371. The next prime is 639099968503. The reversal of 639099968400 is 4869990936.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 789987196 + ... + 789988004.

It is an arithmetic number, because the mean of its divisors is an integer number (4782032100).

Almost surely, 2^639099968400 is an apocalyptic number.

639099968400 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 639099968400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1147687704000).

639099968400 is an abundant number, since it is smaller than the sum of its proper divisors (1656275439600).

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

639099968400 is a wasteful number, since it uses less digits than its factorization.

639099968400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1408 (or 1391 counting only the distinct ones).

The product of its (nonzero) digits is 22674816, while the sum is 63.

The spelling of 639099968400 in words is "six hundred thirty-nine billion, ninety-nine million, nine hundred sixty-eight thousand, four hundred".