21222200 has 48 divisors (see below), whose sum is σ = 51057000. Its totient is φ = 8193920.

The previous prime is 21222181. The next prime is 21222211. The reversal of 21222200 is 222212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3971 + ... + 7629.

Almost surely, 2^21222200 is an apocalyptic number.

21222200 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 21222200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25528500).

21222200 is an abundant number, since it is smaller than the sum of its proper divisors (29834800).

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

21222200 is a wasteful number, since it uses less digits than its factorization.

21222200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3704 (or 3695 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 11.

The square root of 21222200 is about 4606.7559084458. The cubic root of 21222200 is about 276.8620738530.

Adding to 21222200 its reverse (222212), we get a palindrome (21444412).

The spelling of 21222200 in words is "twenty-one million, two hundred twenty-two thousand, two hundred".