640039545600 has 864 divisors, whose sum is σ = 2633184798720. Its totient is φ = 133303173120.

The previous prime is 640039545581. The next prime is 640039545601. The reversal of 640039545600 is 6545930046.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (640039545601) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 138026482 + ... + 138031118.

Almost surely, 2^640039545600 is an apocalyptic number.

640039545600 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 640039545600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1316592399360).

640039545600 is an abundant number, since it is smaller than the sum of its proper divisors (1993145253120).

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

640039545600 is a wasteful number, since it uses less digits than its factorization.

640039545600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4765 (or 4746 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 42.

The spelling of 640039545600 in words is "six hundred forty billion, thirty-nine million, five hundred forty-five thousand, six hundred".