639321984000 has 1760 divisors, whose sum is σ = 2848788873216. Its totient is φ = 139412275200.

The previous prime is 639321983999. The next prime is 639321984011. The reversal of 639321984000 is 489123936.

It is a happy number.

639321984000 is a `hidden beast` number, since 6 + 393 + 219 + 8 + 40 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 1669247809 + ... + 1669248191.

Almost surely, 2^639321984000 is an apocalyptic number.

639321984000 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 639321984000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1424394436608).

639321984000 is an abundant number, since it is smaller than the sum of its proper divisors (2209466889216).

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

639321984000 is a wasteful number, since it uses less digits than its factorization.

639321984000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 460 (or 423 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 45.

The spelling of 639321984000 in words is "six hundred thirty-nine billion, three hundred twenty-one million, nine hundred eighty-four thousand".