21092812 has 48 divisors (see below), whose sum is σ = 43049440. Its totient is φ = 8957952.

The previous prime is 21092789. The next prime is 21092821. The reversal of 21092812 is 21829012.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36268 + ... + 36844.

Almost surely, 2^21092812 is an apocalyptic number.

It is an amenable number.

21092812 is an abundant number, since it is smaller than the sum of its proper divisors (21956628).

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

21092812 is a wasteful number, since it uses less digits than its factorization.

21092812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 650 (or 648 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 21092812 is about 4592.6911500775. The cubic root of 21092812 is about 276.2982667859.

It can be divided in two parts, 21092 and 812, that added together give a square (21904 = 148²).

The spelling of 21092812 in words is "twenty-one million, ninety-two thousand, eight hundred twelve".