21249892 has 6 divisors (see below), whose sum is σ = 37187318. Its totient is φ = 10624944.

The previous prime is 21249871. The next prime is 21249913. The reversal of 21249892 is 29894212.

It is an interprime number because it is at equal distance from previous prime (21249871) and next prime (21249913).

It can be written as a sum of positive squares in only one way, i.e., 17842176 + 3407716 = 4224^2 + 1846^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2656233 + ... + 2656240.

Almost surely, 2^21249892 is an apocalyptic number.

It is an amenable number.

21249892 is a deficient number, since it is larger than the sum of its proper divisors (15937426).

21249892 is a wasteful number, since it uses less digits than its factorization.

21249892 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5312477 (or 5312475 counting only the distinct ones).

The product of its digits is 20736, while the sum is 37.

The square root of 21249892 is about 4609.7605143868. The cubic root of 21249892 is about 276.9824435953.

The spelling of 21249892 in words is "twenty-one million, two hundred forty-nine thousand, eight hundred ninety-two".