640922001408 has 448 divisors, whose sum is σ = 2061175374720. Its totient is φ = 195646980096.

The previous prime is 640922001323. The next prime is 640922001413. The reversal of 640922001408 is 804100229046.

640922001408 is a `hidden beast` number, since 6 + 40 + 9 + 2 + 200 + 1 + 408 = 666.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 393927891 + ... + 393929517.

It is an arithmetic number, because the mean of its divisors is an integer number (4600837890).

Almost surely, 2^640922001408 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 640922001408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1030587687360).

640922001408 is an abundant number, since it is smaller than the sum of its proper divisors (1420253373312).

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

640922001408 is a wasteful number, since it uses less digits than its factorization.

640922001408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1812 (or 1782 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The spelling of 640922001408 in words is "six hundred forty billion, nine hundred twenty-two million, one thousand, four hundred eight".