21613430356 has 24 divisors (see below), whose sum is σ = 43232959616. Its totient is φ = 9261591840.

The previous prime is 21613430347. The next prime is 21613430381. The reversal of 21613430356 is 65303431612.

It is a congruent number.

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, 162745 + ... + 264031.

Almost surely, 2^21613430356 is an apocalyptic number.

It is an amenable number.

21613430356 is an abundant number, since it is smaller than the sum of its proper divisors (21619529260).

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

21613430356 is a wasteful number, since it uses less digits than its factorization.

21613430356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108919 (or 108917 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 34.

Adding to 21613430356 its reverse (65303431612), we get a palindrome (86916861968).

The spelling of 21613430356 in words is "twenty-one billion, six hundred thirteen million, four hundred thirty thousand, three hundred fifty-six".