639400345600 has 204 divisors, whose sum is σ = 1636982418880. Its totient is φ = 247490150400.

The previous prime is 639400345583. The next prime is 639400345601. The reversal of 639400345600 is 6543004936.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (639400345601) 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, 50784106 + ... + 50796694.

Almost surely, 2^639400345600 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 639400345600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (818491209440).

639400345600 is an abundant number, since it is smaller than the sum of its proper divisors (997582073280).

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

639400345600 is an equidigital number, since it uses as much as digits as its factorization.

639400345600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12662 (or 12627 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 40.

The spelling of 639400345600 in words is "six hundred thirty-nine billion, four hundred million, three hundred forty-five thousand, six hundred".