640410408 has 192 divisors, whose sum is σ = 1982232000. Its totient is φ = 191410560.

The previous prime is 640410403. The next prime is 640410439. The reversal of 640410408 is 804014046.

640410408 is a `hidden beast` number, since 640 + 4 + 10 + 4 + 0 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (640410403) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2796438 + ... + 2796666.

It is an arithmetic number, because the mean of its divisors is an integer number (10324125).

Almost surely, 2^640410408 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 640410408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (991116000).

640410408 is an abundant number, since it is smaller than the sum of its proper divisors (1341821592).

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

640410408 is a wasteful number, since it uses less digits than its factorization.

640410408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 373 (or 352 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

The square root of 640410408 is about 25306.3313816918. The cubic root of 640410408 is about 861.9580444083.

The spelling of 640410408 in words is "six hundred forty million, four hundred ten thousand, four hundred eight".