25221328 has 40 divisors (see below), whose sum is σ = 54460800. Its totient is φ = 11216640.

The previous prime is 25221323. The next prime is 25221337. The reversal of 25221328 is 82312252.

It is a super-2 number, since 2×25221328² = 1272230772167168, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25221323) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6748 + ... + 9796.

It is an arithmetic number, because the mean of its divisors is an integer number (1361520).

Almost surely, 2^25221328 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 25221328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27230400).

25221328 is an abundant number, since it is smaller than the sum of its proper divisors (29239472).

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

25221328 is a wasteful number, since it uses less digits than its factorization.

25221328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3115 (or 3109 counting only the distinct ones).

The product of its digits is 1920, while the sum is 25.

The square root of 25221328 is about 5022.0840295638. The cubic root of 25221328 is about 293.2621291818.

The spelling of 25221328 in words is "twenty-five million, two hundred twenty-one thousand, three hundred twenty-eight".