21982528 has 28 divisors (see below), whose sum is σ = 44083732. Its totient is φ = 10874880.

The previous prime is 21982517. The next prime is 21982531. The reversal of 21982528 is 82528912.

It can be written as a sum of positive squares in 2 ways, for example, as 9535744 + 12446784 = 3088^2 + 3528^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4438 + ... + 7978.

It is an arithmetic number, because the mean of its divisors is an integer number (1574419).

Almost surely, 2^21982528 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 21982528, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22041866).

21982528 is an abundant number, since it is smaller than the sum of its proper divisors (22101204).

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

21982528 is an equidigital number, since it uses as much as digits as its factorization.

21982528 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3650 (or 3640 counting only the distinct ones).

The product of its digits is 23040, while the sum is 37.

The square root of 21982528 is about 4688.5528684233. The cubic root of 21982528 is about 280.1297357970.

The spelling of 21982528 in words is "twenty-one million, nine hundred eighty-two thousand, five hundred twenty-eight".