641690715136 has 33 divisors (see below), whose sum is σ = 1282806023781. Its totient is φ = 320832540672.

The previous prime is 641690715119. The next prime is 641690715161. The reversal of 641690715136 is 631517096146.

It is a happy number.

The square root of 641690715136 is 801056.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 61266150400 + 580424564736 = 247520^2 + 761856^2 .

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 641690715136.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 25621276 + ... + 25646308.

Almost surely, 2^641690715136 is an apocalyptic number.

641690715136 is the 801056-th square number.

It is an amenable number.

641690715136 is a deficient number, since it is larger than the sum of its proper divisors (641115308645).

641690715136 is an frugal number, since it uses more digits than its factorization.

641690715136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50086 (or 25035 counting only the distinct ones).

The product of its (nonzero) digits is 816480, while the sum is 49.

Multiplying 641690715136 by its sum of digits (49), we get a square (31442845041664 = 5607392²).

The spelling of 641690715136 in words is "six hundred forty-one billion, six hundred ninety million, seven hundred fifteen thousand, one hundred thirty-six".