640741052778 has 32 divisors (see below), whose sum is σ = 1314423936000. Its totient is φ = 208144138176.

The previous prime is 640741052753. The next prime is 640741052807. The reversal of 640741052778 is 877250147046.

It is a self number, because there is not a number n which added to its sum of digits gives 640741052778.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6714058 + ... + 6808821.

It is an arithmetic number, because the mean of its divisors is an integer number (41075748000).

Almost surely, 2^640741052778 is an apocalyptic number.

640741052778 is an abundant number, since it is smaller than the sum of its proper divisors (673682883222).

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

640741052778 is a wasteful number, since it uses less digits than its factorization.

640741052778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13523086.

The product of its (nonzero) digits is 2634240, while the sum is 51.

The spelling of 640741052778 in words is "six hundred forty billion, seven hundred forty-one million, fifty-two thousand, seven hundred seventy-eight".