21653703568 has 20 divisors (see below), whose sum is σ = 47947486720. Its totient is φ = 9280158624.

The previous prime is 21653703563. The next prime is 21653703587. The reversal of 21653703568 is 86530735612.

It is not an unprimeable number, because it can be changed into a prime (21653703563) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 96668208 + ... + 96668431.

It is an arithmetic number, because the mean of its divisors is an integer number (2397374336).

Almost surely, 2^21653703568 is an apocalyptic number.

21653703568 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21653703568 is an abundant number, since it is smaller than the sum of its proper divisors (26293783152).

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

21653703568 is a wasteful number, since it uses less digits than its factorization.

21653703568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193336654 (or 193336648 counting only the distinct ones).

The product of its (nonzero) digits is 907200, while the sum is 46.

The spelling of 21653703568 in words is "twenty-one billion, six hundred fifty-three million, seven hundred three thousand, five hundred sixty-eight".