21659897435232 has 480 divisors, whose sum is σ = 68716132138080. Its totient is φ = 5973593342976.

The previous prime is 21659897435201. The next prime is 21659897435233. The reversal of 21659897435232 is 23253479895612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21659897435233) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 5621565018 + ... + 5621568870.

It is an arithmetic number, because the mean of its divisors is an integer number (143158608621).

Almost surely, 2^{21659897435232} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21659897435232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34358066069040).

21659897435232 is an abundant number, since it is smaller than the sum of its proper divisors (47056234702848).

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

21659897435232 is an frugal number, since it uses more digits than its factorization.

21659897435232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3981 (or 3894 counting only the distinct ones).

The product of its digits is 195955200, while the sum is 66.

The spelling of 21659897435232 in words is "twenty-one trillion, six hundred fifty-nine billion, eight hundred ninety-seven million, four hundred thirty-five thousand, two hundred thirty-two".