21912200 has 36 divisors (see below), whose sum is σ = 51100245. Its totient is φ = 8738400.

The previous prime is 21912193. The next prime is 21912211. The reversal of 21912200 is 221912.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 2 ways, for example, as 21473956 + 438244 = 4634^2 + 662^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=3310.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 66035 + ... + 66365.

Almost surely, 2^21912200 is an apocalyptic number.

21912200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21912200

21912200 is an abundant number, since it is smaller than the sum of its proper divisors (29188045).

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

21912200 is an equidigital number, since it uses as much as digits as its factorization.

21912200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 678 (or 338 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 17.

The square root of 21912200 is about 4681.0468914549. The cubic root of 21912200 is about 279.8306799433.

Multiplying 21912200 by its product of nonzero digits (72), we get a square (1577678400 = 39720²).

The spelling of 21912200 in words is "twenty-one million, nine hundred twelve thousand, two hundred".