21243748 has 12 divisors (see below), whose sum is σ = 39133360. Its totient is φ = 10062792.

The previous prime is 21243731. The next prime is 21243769. The reversal of 21243748 is 84734212.

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, 139686 + ... + 139837.

Almost surely, 2^21243748 is an apocalyptic number.

It is an amenable number.

21243748 is a deficient number, since it is larger than the sum of its proper divisors (17889612).

21243748 is a wasteful number, since it uses less digits than its factorization.

21243748 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 279546 (or 279544 counting only the distinct ones).

The product of its digits is 10752, while the sum is 31.

The square root of 21243748 is about 4609.0940541499. The cubic root of 21243748 is about 276.9557462961.

The spelling of 21243748 in words is "twenty-one million, two hundred forty-three thousand, seven hundred forty-eight".