21943756 has 6 divisors (see below), whose sum is σ = 38401580. Its totient is φ = 10971876.

The previous prime is 21943741. The next prime is 21943759. The reversal of 21943756 is 65734912.

It is not an unprimeable number, because it can be changed into a prime (21943759) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2742966 + ... + 2742973.

Almost surely, 2^21943756 is an apocalyptic number.

It is an amenable number.

21943756 is a deficient number, since it is larger than the sum of its proper divisors (16457824).

21943756 is a wasteful number, since it uses less digits than its factorization.

21943756 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5485943 (or 5485941 counting only the distinct ones).

The product of its digits is 45360, while the sum is 37.

The square root of 21943756 is about 4684.4162923464. The cubic root of 21943756 is about 279.9649445909.

The spelling of 21943756 in words is "twenty-one million, nine hundred forty-three thousand, seven hundred fifty-six".