21613662120 has 128 divisors (see below), whose sum is σ = 67708535040. Its totient is φ = 5509109760.

The previous prime is 21613662089. The next prime is 21613662127. The reversal of 21613662120 is 2126631612.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (21613662127) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7563732 + ... + 7566588.

It is an arithmetic number, because the mean of its divisors is an integer number (528972930).

Almost surely, 2^21613662120 is an apocalyptic number.

21613662120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21613662120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33854267520).

21613662120 is an abundant number, since it is smaller than the sum of its proper divisors (46094872920).

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

21613662120 is a wasteful number, since it uses less digits than its factorization.

21613662120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5635 (or 5631 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 30.

The spelling of 21613662120 in words is "twenty-one billion, six hundred thirteen million, six hundred sixty-two thousand, one hundred twenty".