21653353256 has 32 divisors (see below), whose sum is σ = 41157153000. Its totient is φ = 10678711296.

The previous prime is 21653353193. The next prime is 21653353261. The reversal of 21653353256 is 65235335612.

It can be written as a sum of positive squares in 4 ways, for example, as 14940172900 + 6713180356 = 122230^2 + 81934^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 254030 + ... + 328386.

Almost surely, 2^21653353256 is an apocalyptic number.

It is an amenable number.

21653353256 is a deficient number, since it is larger than the sum of its proper divisors (19503799744).

21653353256 is a wasteful number, since it uses less digits than its factorization.

21653353256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74861 (or 74857 counting only the distinct ones).

The product of its digits is 486000, while the sum is 41.

Adding to 21653353256 its reverse (65235335612), we get a palindrome (86888688868).

The spelling of 21653353256 in words is "twenty-one billion, six hundred fifty-three million, three hundred fifty-three thousand, two hundred fifty-six".