21132624 has 80 divisors (see below), whose sum is σ = 57184832. Its totient is φ = 6718464.

The previous prime is 21132623. The next prime is 21132659. The reversal of 21132624 is 42623112.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21132624.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21132623) 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, 129567 + ... + 129729.

Almost surely, 2^21132624 is an apocalyptic number.

21132624 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21132624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28592416).

21132624 is an abundant number, since it is smaller than the sum of its proper divisors (36052208).

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

21132624 is a wasteful number, since it uses less digits than its factorization.

21132624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284 (or 278 counting only the distinct ones).

The product of its digits is 576, while the sum is 21.

The square root of 21132624 is about 4597.0233847567. The cubic root of 21132624 is about 276.4719922101.

Adding to 21132624 its reverse (42623112), we get a palindrome (63755736).

The spelling of 21132624 in words is "twenty-one million, one hundred thirty-two thousand, six hundred twenty-four".