640310171780 has 24 divisors (see below), whose sum is σ = 1345548456000. Its totient is φ = 255953193440.

The previous prime is 640310171779. The next prime is 640310171827. The reversal of 640310171780 is 87171013046.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10648976 + ... + 10708935.

It is an arithmetic number, because the mean of its divisors is an integer number (56064519000).

Almost surely, 2^640310171780 is an apocalyptic number.

It is an amenable number.

640310171780 is an abundant number, since it is smaller than the sum of its proper divisors (705238284220).

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

640310171780 is a wasteful number, since it uses less digits than its factorization.

640310171780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21359419 (or 21359417 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 38.

The spelling of 640310171780 in words is "six hundred forty billion, three hundred ten million, one hundred seventy-one thousand, seven hundred eighty".