21995262864 has 135 divisors (see below), whose sum is σ = 65480205297. Its totient is φ = 6890982912.

The previous prime is 21995262859. The next prime is 21995262901. The reversal of 21995262864 is 46826259912.

The square root of 21995262864 is 148308.

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

21995262864 is a `hidden beast` number, since 2 + 1 + 9 + 9 + 5 + 2 + 628 + 6 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 17124339600 + 4870923264 = 130860^2 + 69792^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21995262864.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 30254469 + ... + 30255195.

Almost surely, 2^21995262864 is an apocalyptic number.

21995262864 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

21995262864 is the 148308-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21995262864

21995262864 is an abundant number, since it is smaller than the sum of its proper divisors (43484942433).

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

21995262864 is an equidigital number, since it uses as much as digits as its factorization.

21995262864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1502 (or 749 counting only the distinct ones).

The product of its digits is 3732480, while the sum is 54.

The spelling of 21995262864 in words is "twenty-one billion, nine hundred ninety-five million, two hundred sixty-two thousand, eight hundred sixty-four".