21552132 has 96 divisors (see below), whose sum is σ = 60383232. Its totient is φ = 5855616.

The previous prime is 21552131. The next prime is 21552143. The reversal of 21552132 is 23125512.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 21552099 and 21552108.

It is not an unprimeable number, because it can be changed into a prime (21552131) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 209193 + ... + 209295.

It is an arithmetic number, because the mean of its divisors is an integer number (628992).

Almost surely, 2^21552132 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21552132, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30191616).

21552132 is an abundant number, since it is smaller than the sum of its proper divisors (38831100).

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

21552132 is a wasteful number, since it uses less digits than its factorization.

21552132 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 217 (or 215 counting only the distinct ones).

The product of its digits is 600, while the sum is 21.

The square root of 21552132 is about 4642.4273823077. The cubic root of 21552132 is about 278.2894523274.

Adding to 21552132 its reverse (23125512), we get a palindrome (44677644).

The spelling of 21552132 in words is "twenty-one million, five hundred fifty-two thousand, one hundred thirty-two".