21893944 has 16 divisors (see below), whose sum is σ = 41132520. Its totient is φ = 10925280.

The previous prime is 21893939. The next prime is 21893987. The reversal of 21893944 is 44939812.

It is a junction number, because it is equal to n+sod(n) for n = 21893897 and 21893906.

It is a congruent number.

It is an unprimeable number.

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, 2074 + ... + 6934.

Almost surely, 2^21893944 is an apocalyptic number.

It is an amenable number.

21893944 is a deficient number, since it is larger than the sum of its proper divisors (19238576).

21893944 is a wasteful number, since it uses less digits than its factorization.

21893944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5430 (or 5426 counting only the distinct ones).

The product of its digits is 62208, while the sum is 40.

The square root of 21893944 is about 4679.0964939826. The cubic root of 21893944 is about 279.7529453437.

The spelling of 21893944 in words is "twenty-one million, eight hundred ninety-three thousand, nine hundred forty-four".