640929380544 has 168 divisors, whose sum is σ = 1871656810400. Its totient is φ = 209654894592.

The previous prime is 640929380489. The next prime is 640929380603. The reversal of 640929380544 is 445083929046.

640929380544 is a `hidden beast` number, since 6 + 4 + 0 + 9 + 2 + 93 + 8 + 0 + 544 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8329254 + ... + 8405850.

Almost surely, 2^640929380544 is an apocalyptic number.

640929380544 is a gapful number since it is divisible by the number (64) 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 640929380544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (935828405200).

640929380544 is an abundant number, since it is smaller than the sum of its proper divisors (1230727429856).

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

640929380544 is a wasteful number, since it uses less digits than its factorization.

640929380544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76887 (or 76874 counting only the distinct ones).

The product of its (nonzero) digits is 7464960, while the sum is 54.

The spelling of 640929380544 in words is "six hundred forty billion, nine hundred twenty-nine million, three hundred eighty thousand, five hundred forty-four".