21579022404 has 45 divisors (see below), whose sum is σ = 56418740301. Its totient is φ = 7192126080.

The previous prime is 21579022391. The next prime is 21579022417. The reversal of 21579022404 is 40422097512.

The square root of 21579022404 is 146898.

It is a perfect power (a square), and thus also a powerful number.

21579022404 is a `hidden beast` number, since 21 + 579 + 0 + 22 + 40 + 4 = 666.

It is an interprime number because it is at equal distance from previous prime (21579022391) and next prime (21579022417).

It can be written as a sum of positive squares in only one way, i.e., 7974132804 + 13604889600 = 89298^2 + 116640^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 2640084 + ... + 2648244.

Almost surely, 2^21579022404 is an apocalyptic number.

21579022404 is the 146898-th square number.

It is an amenable number.

21579022404 is an abundant number, since it is smaller than the sum of its proper divisors (34839717897).

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

21579022404 is an frugal number, since it uses more digits than its factorization.

21579022404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16338 (or 8166 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

Multiplying 21579022404 by its sum of digits (36), we get a square (776844806544 = 881388²).

21579022404 divided by its sum of digits (36) gives a square (599417289 = 24483²).

The spelling of 21579022404 in words is "twenty-one billion, five hundred seventy-nine million, twenty-two thousand, four hundred four".