21532128 has 48 divisors (see below), whose sum is σ = 56843136. Its totient is φ = 7136640.

The previous prime is 21532097. The next prime is 21532169. The reversal of 21532128 is 82123512.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a junction number, because it is equal to n+sod(n) for n = 21532098 and 21532107.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19725 + ... + 20787.

It is an arithmetic number, because the mean of its divisors is an integer number (1184232).

Almost surely, 2^21532128 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 21532128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28421568).

21532128 is an abundant number, since it is smaller than the sum of its proper divisors (35311008).

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

21532128 is a wasteful number, since it uses less digits than its factorization.

21532128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1287 (or 1279 counting only the distinct ones).

The product of its digits is 960, while the sum is 24.

The square root of 21532128 is about 4640.2724057969. The cubic root of 21532128 is about 278.2033258840.

The spelling of 21532128 in words is "twenty-one million, five hundred thirty-two thousand, one hundred twenty-eight".