21885424 has 20 divisors (see below), whose sum is σ = 46258200. Its totient is φ = 9947840.

The previous prime is 21885407. The next prime is 21885427. The reversal of 21885424 is 42458812.

It is a self number, because there is not a number n which added to its sum of digits gives 21885424.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21885427) 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, 61999 + ... + 62350.

It is an arithmetic number, because the mean of its divisors is an integer number (2312910).

Almost surely, 2^21885424 is an apocalyptic number.

It is an amenable number.

21885424 is an abundant number, since it is smaller than the sum of its proper divisors (24372776).

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

21885424 is a wasteful number, since it uses less digits than its factorization.

21885424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124368 (or 124362 counting only the distinct ones).

The product of its digits is 20480, while the sum is 34.

The square root of 21885424 is about 4678.1859732165. The cubic root of 21885424 is about 279.7166521365.

The spelling of 21885424 in words is "twenty-one million, eight hundred eighty-five thousand, four hundred twenty-four".