21613180728 has 32 divisors (see below), whose sum is σ = 54038419200. Its totient is φ = 7203664608.

The previous prime is 21613180727. The next prime is 21613180733. The reversal of 21613180728 is 82708131612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21613180727) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 230775 + ... + 310617.

It is an arithmetic number, because the mean of its divisors is an integer number (1688700600).

Almost surely, 2^21613180728 is an apocalyptic number.

It is an amenable number.

21613180728 is an abundant number, since it is smaller than the sum of its proper divisors (32425238472).

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

21613180728 is a wasteful number, since it uses less digits than its factorization.

21613180728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91131 (or 91127 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 39.

The spelling of 21613180728 in words is "twenty-one billion, six hundred thirteen million, one hundred eighty thousand, seven hundred twenty-eight".