21012044 has 12 divisors (see below), whose sum is σ = 36813168. Its totient is φ = 10494000.

The previous prime is 21011981. The next prime is 21012053. The reversal of 21012044 is 44021012.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1769 + ... + 6719.

It is an arithmetic number, because the mean of its divisors is an integer number (3067764).

Almost surely, 2^21012044 is an apocalyptic number.

It is an amenable number.

21012044 is a deficient number, since it is larger than the sum of its proper divisors (15801124).

21012044 is a wasteful number, since it uses less digits than its factorization.

21012044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6016 (or 6014 counting only the distinct ones).

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

The square root of 21012044 is about 4583.8896147268. The cubic root of 21012044 is about 275.9451511815.

Adding to 21012044 its reverse (44021012), we get a palindrome (65033056).

The spelling of 21012044 in words is "twenty-one million, twelve thousand, forty-four".