21244044 has 12 divisors (see below), whose sum is σ = 49569464. Its totient is φ = 7081344.

The previous prime is 21244001. The next prime is 21244061. The reversal of 21244044 is 44044212.

It is a tau number, because it is divible by the number of its divisors (12).

It is a self number, because there is not a number n which added to its sum of digits gives 21244044.

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, 885157 + ... + 885180.

Almost surely, 2^21244044 is an apocalyptic number.

It is an amenable number.

21244044 is an abundant number, since it is smaller than the sum of its proper divisors (28325420).

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

21244044 is a wasteful number, since it uses less digits than its factorization.

21244044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1770344 (or 1770342 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 21.

The square root of 21244044 is about 4609.1261644698. The cubic root of 21244044 is about 276.9570326121.

Adding to 21244044 its reverse (44044212), we get a palindrome (65288256).

The spelling of 21244044 in words is "twenty-one million, two hundred forty-four thousand, forty-four".