21022200 has 192 divisors, whose sum is σ = 77004000. Its totient is φ = 5253120.

The previous prime is 21022193. The next prime is 21022213. The reversal of 21022200 is 222012.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

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 47 ways as a sum of consecutive naturals, for example, 91686 + ... + 91914.

Almost surely, 2^21022200 is an apocalyptic number.

21022200 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 21022200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38502000).

21022200 is an abundant number, since it is smaller than the sum of its proper divisors (55981800).

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

21022200 is a wasteful number, since it uses less digits than its factorization.

21022200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 271 (or 256 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 9.

The square root of 21022200 is about 4584.9972737178. The cubic root of 21022200 is about 275.9896026329.

Adding to 21022200 its reverse (222012), we get a palindrome (21244212).

The spelling of 21022200 in words is "twenty-one million, twenty-two thousand, two hundred".