21944128 has 28 divisors (see below), whose sum is σ = 43789600. Its totient is φ = 10910592.

The previous prime is 21944123. The next prime is 21944137. The reversal of 21944128 is 82144912.

It is a self number, because there is not a number n which added to its sum of digits gives 21944128.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21944123) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11875 + ... + 13597.

Almost surely, 2^21944128 is an apocalyptic number.

It is an amenable number.

21944128 is a deficient number, since it is larger than the sum of its proper divisors (21845472).

21944128 is a wasteful number, since it uses less digits than its factorization.

21944128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1934 (or 1924 counting only the distinct ones).

The product of its digits is 4608, while the sum is 31.

The square root of 21944128 is about 4684.4559982991. The cubic root of 21944128 is about 279.9665266107.

The spelling of 21944128 in words is "twenty-one million, nine hundred forty-four thousand, one hundred twenty-eight".