21641587694508 has 48 divisors (see below), whose sum is σ = 50510744817120. Its totient is φ = 7211904758784.

The previous prime is 21641587694413. The next prime is 21641587694509. The reversal of 21641587694508 is 80549678514612.

It is not an unprimeable number, because it can be changed into a prime (21641587694509) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1184597998 + ... + 1184616266.

It is an arithmetic number, because the mean of its divisors is an integer number (1052307183690).

Almost surely, 2^{21641587694508} is an apocalyptic number.

It is an amenable number.

21641587694508 is an abundant number, since it is smaller than the sum of its proper divisors (28869157122612).

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

21641587694508 is a wasteful number, since it uses less digits than its factorization.

21641587694508 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39666 (or 39664 counting only the distinct ones).

The product of its (nonzero) digits is 116121600, while the sum is 66.

The spelling of 21641587694508 in words is "twenty-one trillion, six hundred forty-one billion, five hundred eighty-seven million, six hundred ninety-four thousand, five hundred eight".