21943224 has 40 divisors (see below), whose sum is σ = 61463160. Its totient is φ = 7314192.

The previous prime is 21943213. The next prime is 21943231. The reversal of 21943224 is 42234912.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 16284 + ... + 17579.

It is an arithmetic number, because the mean of its divisors is an integer number (1536579).

Almost surely, 2^21943224 is an apocalyptic number.

21943224 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21943224 is an abundant number, since it is smaller than the sum of its proper divisors (39519936).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21943224 is a wasteful number, since it uses less digits than its factorization.

21943224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33881 (or 33868 counting only the distinct ones).

The product of its digits is 3456, while the sum is 27.

The square root of 21943224 is about 4684.3595079797. The cubic root of 21943224 is about 279.9626821014.

The spelling of 21943224 in words is "twenty-one million, nine hundred forty-three thousand, two hundred twenty-four".