21044472 has 16 divisors (see below), whose sum is σ = 52611240. Its totient is φ = 7014816.

The previous prime is 21044467. The next prime is 21044473. The reversal of 21044472 is 27444012.

It is a Harshad number since it is a multiple of its sum of digits (24), and also a Moran number because the ratio is a prime number: 876853 = 21044472 / (2 + 1 + 0 + 4 + 4 + 4 + 7 + 2).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21044473) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 438403 + ... + 438450.

Almost surely, 2^21044472 is an apocalyptic number.

It is an amenable number.

21044472 is an abundant number, since it is smaller than the sum of its proper divisors (31566768).

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

21044472 is a wasteful number, since it uses less digits than its factorization.

21044472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 876862 (or 876858 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 24.

The square root of 21044472 is about 4587.4254217371. The cubic root of 21044472 is about 276.0870340934.

Adding to 21044472 its reverse (27444012), we get a palindrome (48488484).

The spelling of 21044472 in words is "twenty-one million, forty-four thousand, four hundred seventy-two".