21222662400 has 243 divisors, whose sum is σ = 76001015181. Its totient is φ = 5650053120.

The previous prime is 21222662393. The next prime is 21222662411. The reversal of 21222662400 is 426622212.

It is a happy number.

The square root of 21222662400 is 145680.

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

21222662400 is a `hidden beast` number, since 2 + 12 + 2 + 26 + 624 + 0 + 0 = 666.

It can be written as a sum of positive squares in only one way, i.e., 7640158464 + 13582503936 = 87408^2 + 116544^2 .

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, 34962897 + ... + 34963503.

Almost surely, 2^21222662400 is an apocalyptic number.

21222662400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

21222662400 is the 145680-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21222662400

21222662400 is an abundant number, since it is smaller than the sum of its proper divisors (54778352781).

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

21222662400 is an frugal number, since it uses more digits than its factorization.

21222662400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1246 (or 617 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

The spelling of 21222662400 in words is "twenty-one billion, two hundred twenty-two million, six hundred sixty-two thousand, four hundred".