21442528 has 48 divisors (see below), whose sum is σ = 44089920. Its totient is φ = 10256896.

The previous prime is 21442501. The next prime is 21442543. The reversal of 21442528 is 82524412.

It is a junction number, because it is equal to n+sod(n) for n = 21442496 and 21442505.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 79578 + ... + 79846.

It is an arithmetic number, because the mean of its divisors is an integer number (918540).

Almost surely, 2^21442528 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 21442528, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22044960).

21442528 is an abundant number, since it is smaller than the sum of its proper divisors (22647392).

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

21442528 is a wasteful number, since it uses less digits than its factorization.

21442528 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 379 (or 371 counting only the distinct ones).

The product of its digits is 5120, while the sum is 28.

The square root of 21442528 is about 4630.6077354922. The cubic root of 21442528 is about 277.8169006348.

The spelling of 21442528 in words is "twenty-one million, four hundred forty-two thousand, five hundred twenty-eight".