21226158864 has 315 divisors, whose sum is σ = 66005879799. Its totient is φ = 6608589120.

The previous prime is 21226158859. The next prime is 21226158901. The reversal of 21226158864 is 46885162212.

The square root of 21226158864 is 145692.

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

21226158864 is a `hidden beast` number, since 2 + 1 + 2 + 2 + 6 + 1 + 588 + 64 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 298959949 + ... + 298960019.

Almost surely, 2^21226158864 is an apocalyptic number.

21226158864 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

21226158864 is the 145692-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21226158864

21226158864 is an abundant number, since it is smaller than the sum of its proper divisors (44779720935).

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

21226158864 is an frugal number, since it uses more digits than its factorization.

21226158864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206 (or 95 counting only the distinct ones).

The product of its digits is 368640, while the sum is 45.

The spelling of 21226158864 in words is "twenty-one billion, two hundred twenty-six million, one hundred fifty-eight thousand, eight hundred sixty-four".