28225 has 6 divisors (see below), whose sum is σ = 35030. Its totient is φ = 22560.

The previous prime is 28219. The next prime is 28229. The reversal of 28225 is 52282.

It is a Cunningham number, because it is equal to 168²+1.

It can be written as a sum of positive squares in 3 ways, for example, as 1 + 28224 = 1^2 + 168^2 .

It is not a de Polignac number, because 28225 - 2⁷ = 28097 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 540 + ... + 589.

2²⁸²²⁵ is an apocalyptic number.

28225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28225 is a deficient number, since it is larger than the sum of its proper divisors (6805).

28225 is a wasteful number, since it uses less digits than its factorization.

28225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1139 (or 1134 counting only the distinct ones).

The product of its digits is 320, while the sum is 19.

The square root of 28225 is about 168.0029761641. The cubic root of 28225 is about 30.4470100233.

It can be divided in two parts, 28 and 225, that added together give a triangular number (253 = T₂₂).

The spelling of 28225 in words is "twenty-eight thousand, two hundred twenty-five".