21222540576 has 144 divisors (see below), whose sum is σ = 62517382200. Its totient is φ = 6820982784.

The previous prime is 21222540551. The next prime is 21222540583. The reversal of 21222540576 is 67504522212.

21222540576 is a `hidden beast` number, since 2 + 1 + 22 + 25 + 40 + 576 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 17218688400 + 4003852176 = 131220^2 + 63276^2 .

It is a tau number, because it is divible by the number of its divisors (144).

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

It is a self number, because there is not a number n which added to its sum of digits gives 21222540576.

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, 8927100 + ... + 8929476.

Almost surely, 2^21222540576 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 21222540576, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31258691100).

21222540576 is an abundant number, since it is smaller than the sum of its proper divisors (41294841624).

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

21222540576 is a wasteful number, since it uses less digits than its factorization.

21222540576 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3491 (or 3480 counting only the distinct ones).

The product of its (nonzero) digits is 67200, while the sum is 36.

The spelling of 21222540576 in words is "twenty-one billion, two hundred twenty-two million, five hundred forty thousand, five hundred seventy-six".