21113300 has 72 divisors (see below), whose sum is σ = 50127000. Its totient is φ = 7672320.

The previous prime is 21113299. The next prime is 21113317. The reversal of 21113300 is 331112.

It can be written as a sum of positive squares in 12 ways, for example, as 11847364 + 9265936 = 3442^2 + 3044^2 .

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, 141626 + ... + 141774.

Almost surely, 2^21113300 is an apocalyptic number.

21113300 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 21113300, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25063500).

21113300 is an abundant number, since it is smaller than the sum of its proper divisors (29013700).

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

21113300 is a wasteful number, since it uses less digits than its factorization.

21113300 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 285 (or 278 counting only the distinct ones).

The product of its (nonzero) digits is 18, while the sum is 11.

The square root of 21113300 is about 4594.9211092248. The cubic root of 21113300 is about 276.3876964148.

Adding to 21113300 its reverse (331112), we get a palindrome (21444412).

The spelling of 21113300 in words is "twenty-one million, one hundred thirteen thousand, three hundred".