21289892 has 24 divisors (see below), whose sum is σ = 40262712. Its totient is φ = 9792000.

The previous prime is 21289889. The next prime is 21289907. The reversal of 21289892 is 29898212.

It can be written as a sum of positive squares in 4 ways, for example, as 6421156 + 14868736 = 2534^2 + 3856^2 .

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, 20342 + ... + 21362.

It is an arithmetic number, because the mean of its divisors is an integer number (1677613).

Almost surely, 2^21289892 is an apocalyptic number.

It is an amenable number.

21289892 is a deficient number, since it is larger than the sum of its proper divisors (18972820).

21289892 is a wasteful number, since it uses less digits than its factorization.

21289892 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1439 (or 1437 counting only the distinct ones).

The product of its digits is 41472, while the sum is 41.

The square root of 21289892 is about 4614.0970947738. The cubic root of 21289892 is about 277.1561284506.

The spelling of 21289892 in words is "twenty-one million, two hundred eighty-nine thousand, eight hundred ninety-two".