640930406400 has 672 divisors, whose sum is σ = 2431289625600. Its totient is φ = 165357158400.

The previous prime is 640930406383. The next prime is 640930406437. The reversal of 640930406400 is 4604039046.

640930406400 is a `hidden beast` number, since 6 + 4 + 0 + 9 + 3 + 0 + 4 + 0 + 640 + 0 = 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 a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 171415731 + ... + 171419469.

Almost surely, 2^640930406400 is an apocalyptic number.

640930406400 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 640930406400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1215644812800).

640930406400 is an abundant number, since it is smaller than the sum of its proper divisors (1790359219200).

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

640930406400 is a wasteful number, since it uses less digits than its factorization.

640930406400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3815 (or 3780 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 36.

The spelling of 640930406400 in words is "six hundred forty billion, nine hundred thirty million, four hundred six thousand, four hundred".