21894736 has 20 divisors (see below), whose sum is σ = 42934752. Its totient is φ = 10814816.

The previous prime is 21894703. The next prime is 21894737. The reversal of 21894736 is 63749812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21894737) 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, 6916 + ... + 9571.

Almost surely, 2^21894736 is an apocalyptic number.

It is an amenable number.

21894736 is a deficient number, since it is larger than the sum of its proper divisors (21040016).

21894736 is a wasteful number, since it uses less digits than its factorization.

21894736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16578 (or 16572 counting only the distinct ones).

The product of its digits is 72576, while the sum is 40.

The square root of 21894736 is about 4679.1811249406. The cubic root of 21894736 is about 279.7563186001.

The spelling of 21894736 in words is "twenty-one million, eight hundred ninety-four thousand, seven hundred thirty-six".