21111204 has 24 divisors (see below), whose sum is σ = 51852640. Its totient is φ = 6666624.

The previous prime is 21111199. The next prime is 21111239. The reversal of 21111204 is 40211112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a self number, because there is not a number n which added to its sum of digits gives 21111204.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46069 + ... + 46524.

Almost surely, 2^21111204 is an apocalyptic number.

It is an amenable number.

21111204 is an abundant number, since it is smaller than the sum of its proper divisors (30741436).

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

21111204 is a wasteful number, since it uses less digits than its factorization.

21111204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92619 (or 92617 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 21111204 is about 4594.6930256547. The cubic root of 21111204 is about 276.3785500823.

Adding to 21111204 its reverse (40211112), we get a palindrome (61322316).

The spelling of 21111204 in words is "twenty-one million, one hundred eleven thousand, two hundred four".