21225300 has 72 divisors (see below), whose sum is σ = 61975200. Its totient is φ = 5608320.

The previous prime is 21225293. The next prime is 21225311. The reversal of 21225300 is 352212.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21225300.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 41446 + ... + 41954.

Almost surely, 2^21225300 is an apocalyptic number.

21225300 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 21225300, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30987600).

21225300 is an abundant number, since it is smaller than the sum of its proper divisors (40749900).

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

21225300 is a wasteful number, since it uses less digits than its factorization.

21225300 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 665 (or 658 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 15.

The square root of 21225300 is about 4607.0923585272. The cubic root of 21225300 is about 276.8755539295.

Adding to 21225300 its reverse (352212), we get a palindrome (21577512).

The spelling of 21225300 in words is "twenty-one million, two hundred twenty-five thousand, three hundred".