640256102464 has 56 divisors (see below), whose sum is σ = 1405530311616. Its totient is φ = 286926528000.

The previous prime is 640256102461. The next prime is 640256102471. The reversal of 640256102464 is 464201652046.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (640256102461) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6354627 + ... + 6454594.

Almost surely, 2^640256102464 is an apocalyptic number.

640256102464 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

640256102464 is an abundant number, since it is smaller than the sum of its proper divisors (765274209152).

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

640256102464 is a wasteful number, since it uses less digits than its factorization.

640256102464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12809315 (or 12809305 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 40.

The spelling of 640256102464 in words is "six hundred forty billion, two hundred fifty-six million, one hundred two thousand, four hundred sixty-four".