21120044 has 24 divisors (see below), whose sum is σ = 41413008. Its totient is φ = 9339840.

The previous prime is 21120041. The next prime is 21120067. The reversal of 21120044 is 44002112.

It is not an unprimeable number, because it can be changed into a prime (21120041) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4859 + ... + 8114.

It is an arithmetic number, because the mean of its divisors is an integer number (1725542).

Almost surely, 2^21120044 is an apocalyptic number.

It is an amenable number.

21120044 is a deficient number, since it is larger than the sum of its proper divisors (20292964).

21120044 is a wasteful number, since it uses less digits than its factorization.

21120044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13025 (or 13023 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 21120044 is about 4595.6549043635. The cubic root of 21120044 is about 276.4171211565.

Adding to 21120044 its reverse (44002112), we get a palindrome (65122156).

The spelling of 21120044 in words is "twenty-one million, one hundred twenty thousand, forty-four".