21606565997592 has 64 divisors (see below), whose sum is σ = 60863566233600. Its totient is φ = 7100749383840.

The previous prime is 21606565997579. The next prime is 21606565997603. The reversal of 21606565997592 is 29579956560612.

21606565997592 is a `hidden beast` number, since 2 + 1 + 6 + 0 + 6 + 565 + 9 + 9 + 7 + 59 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a self number, because there is not a number n which added to its sum of digits gives 21606565997592.

It is a congruent number.

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, 704424088 + ... + 704454759.

It is an arithmetic number, because the mean of its divisors is an integer number (950993222400).

Almost surely, 2^{21606565997592} is an apocalyptic number.

It is an amenable number.

21606565997592 is an abundant number, since it is smaller than the sum of its proper divisors (39257000236008).

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

21606565997592 is a wasteful number, since it uses less digits than its factorization.

21606565997592 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1408878933 (or 1408878923 counting only the distinct ones).

The product of its (nonzero) digits is 551124000, while the sum is 72.

The spelling of 21606565997592 in words is "twenty-one trillion, six hundred six billion, five hundred sixty-five million, nine hundred ninety-seven thousand, five hundred ninety-two".