28249225 has 9 divisors (see below), whose sum is σ = 35062023. Its totient is φ = 22578120.

The previous prime is 28249187. The next prime is 28249229. The reversal of 28249225 is 52294282.

The square root of 28249225 is 5315.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 10169721 + 18079504 = 3189^2 + 4252^2 .

It is not a de Polignac number, because 28249225 - 2⁷ = 28249097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28249229) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 26044 + ... + 27106.

Almost surely, 2^28249225 is an apocalyptic number.

28249225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

28249225 is the 5315-th square number.

28249225 is the 2658-th centered octagonal number.

It is an amenable number.

28249225 is a deficient number, since it is larger than the sum of its proper divisors (6812798).

28249225 is an frugal number, since it uses more digits than its factorization.

28249225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2136 (or 1068 counting only the distinct ones).

The product of its digits is 23040, while the sum is 34.

The cubic root of 28249225 is about 304.5571823589.

The spelling of 28249225 in words is "twenty-eight million, two hundred forty-nine thousand, two hundred twenty-five".