21874624 has 28 divisors (see below), whose sum is σ = 45694600. Its totient is φ = 10361088.

The previous prime is 21874621. The next prime is 21874627. The reversal of 21874624 is 42647812.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21874621) and next prime (21874627).

It is a self number, because there is not a number n which added to its sum of digits gives 21874624.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21874621) 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, 7779 + ... + 10210.

It is an arithmetic number, because the mean of its divisors is an integer number (1631950).

Almost surely, 2^21874624 is an apocalyptic number.

It is an amenable number.

21874624 is an abundant number, since it is smaller than the sum of its proper divisors (23819976).

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

21874624 is a wasteful number, since it uses less digits than its factorization.

21874624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18020 (or 18010 counting only the distinct ones).

The product of its digits is 21504, while the sum is 34.

The square root of 21874624 is about 4677.0315372039. The cubic root of 21874624 is about 279.6706331224.

The spelling of 21874624 in words is "twenty-one million, eight hundred seventy-four thousand, six hundred twenty-four".