21044992 has 18 divisors (see below), whose sum is σ = 42008288. Its totient is φ = 10522368.

The previous prime is 21044987. The next prime is 21044993. The reversal of 21044992 is 29944012.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21044993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40848 + ... + 41359.

Almost surely, 2^21044992 is an apocalyptic number.

It is an amenable number.

21044992 is a deficient number, since it is larger than the sum of its proper divisors (20963296).

21044992 is an frugal number, since it uses more digits than its factorization.

21044992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82223 (or 82209 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 21044992 is about 4587.4820980577. The cubic root of 21044992 is about 276.0893080726.

The spelling of 21044992 in words is "twenty-one million, forty-four thousand, nine hundred ninety-two".