21044044 has 24 divisors (see below), whose sum is σ = 42398720. Its totient is φ = 8952336.

The previous prime is 21044003. The next prime is 21044047. The reversal of 21044044 is 44044012.

It is not an unprimeable number, because it can be changed into a prime (21044047) 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, 1189 + ... + 6595.

Almost surely, 2^21044044 is an apocalyptic number.

It is an amenable number.

21044044 is an abundant number, since it is smaller than the sum of its proper divisors (21354676).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21044044 is a wasteful number, since it uses less digits than its factorization.

21044044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5557 (or 5555 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 19.

The square root of 21044044 is about 4587.3787722402. The cubic root of 21044044 is about 276.0851624055.

Adding to 21044044 its reverse (44044012), we get a palindrome (65088056).

The spelling of 21044044 in words is "twenty-one million, forty-four thousand, forty-four".