21943384 has 16 divisors (see below), whose sum is σ = 41193720. Its totient is φ = 10958400.

The previous prime is 21943351. The next prime is 21943387. The reversal of 21943384 is 48334912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21943387) 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, 11284 + ... + 13084.

Almost surely, 2^21943384 is an apocalyptic number.

It is an amenable number.

21943384 is a deficient number, since it is larger than the sum of its proper divisors (19250336).

21943384 is a wasteful number, since it uses less digits than its factorization.

21943384 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3330 (or 3326 counting only the distinct ones).

The product of its digits is 20736, while the sum is 34.

The square root of 21943384 is about 4684.3765860571. The cubic root of 21943384 is about 279.9633625532.

The spelling of 21943384 in words is "twenty-one million, nine hundred forty-three thousand, three hundred eighty-four".