28515225 has 12 divisors (see below), whose sum is σ = 47145296. Its totient is φ = 15208080.

The previous prime is 28515217. The next prime is 28515247. The reversal of 28515225 is 52251582.

It is not a de Polignac number, because 28515225 - 2³ = 28515217 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28515192 and 28515201.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 190027 + ... + 190176.

Almost surely, 2^28515225 is an apocalyptic number.

28515225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28515225 is a deficient number, since it is larger than the sum of its proper divisors (18630071).

28515225 is a wasteful number, since it uses less digits than its factorization.

28515225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 380216 (or 380211 counting only the distinct ones).

The product of its digits is 8000, while the sum is 30.

The square root of 28515225 is about 5339.9648875250. The cubic root of 28515225 is about 305.5101200884.

The spelling of 28515225 in words is "twenty-eight million, five hundred fifteen thousand, two hundred twenty-five".