21875232 has 96 divisors (see below), whose sum is σ = 61689600. Its totient is φ = 6766848.

The previous prime is 21875207. The next prime is 21875233. The reversal of 21875232 is 23257812.

It is a tau number, because it is divible by the number of its divisors (96).

It is a self number, because there is not a number n which added to its sum of digits gives 21875232.

It is not an unprimeable number, because it can be changed into a prime (21875233) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 122119 + ... + 122297.

It is an arithmetic number, because the mean of its divisors is an integer number (642600).

Almost surely, 2^21875232 is an apocalyptic number.

21875232 is the 3819-th pentagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21875232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30844800).

21875232 is an abundant number, since it is smaller than the sum of its proper divisors (39814368).

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

21875232 is a wasteful number, since it uses less digits than its factorization.

21875232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278 (or 270 counting only the distinct ones).

The product of its digits is 6720, while the sum is 30.

The square root of 21875232 is about 4677.0965352449. The cubic root of 21875232 is about 279.6732242248.

The spelling of 21875232 in words is "twenty-one million, eight hundred seventy-five thousand, two hundred thirty-two".