21113699964 has 72 divisors (see below), whose sum is σ = 57526939008. Its totient is φ = 6009504480.

The previous prime is 21113699923. The next prime is 21113699989. The reversal of 21113699964 is 46999631112.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 86379 + ... + 222909.

It is an arithmetic number, because the mean of its divisors is an integer number (798985264).

Almost surely, 2^21113699964 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21113699964, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28763469504).

21113699964 is an abundant number, since it is smaller than the sum of its proper divisors (36413239044).

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

21113699964 is a wasteful number, since it uses less digits than its factorization.

21113699964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136815 (or 136806 counting only the distinct ones).

The product of its digits is 629856, while the sum is 51.

The spelling of 21113699964 in words is "twenty-one billion, one hundred thirteen million, six hundred ninety-nine thousand, nine hundred sixty-four".