640716866834 has 16 divisors (see below), whose sum is σ = 1065633420096. Its totient is φ = 286460595600.

The previous prime is 640716866789. The next prime is 640716866887. The reversal of 640716866834 is 438668617046.

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, 238715822 + ... + 238718505.

It is an arithmetic number, because the mean of its divisors is an integer number (66602088756).

Almost surely, 2^640716866834 is an apocalyptic number.

640716866834 is a deficient number, since it is larger than the sum of its proper divisors (424916553262).

640716866834 is a wasteful number, since it uses less digits than its factorization.

640716866834 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 477434401.

The product of its (nonzero) digits is 27869184, while the sum is 59.

The spelling of 640716866834 in words is "six hundred forty billion, seven hundred sixteen million, eight hundred sixty-six thousand, eight hundred thirty-four".