28389225 has 12 divisors (see below), whose sum is σ = 46936976. Its totient is φ = 15140880.

The previous prime is 28389223. The next prime is 28389227. The reversal of 28389225 is 52298382.

It is an interprime number because it is at equal distance from previous prime (28389223) and next prime (28389227).

It is not a de Polignac number, because 28389225 - 2¹ = 28389223 is a prime.

It is a super-2 number, since 2×28389225² = 1611896192201250, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28389223) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 189187 + ... + 189336.

Almost surely, 2^28389225 is an apocalyptic number.

28389225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28389225 is a deficient number, since it is larger than the sum of its proper divisors (18547751).

28389225 is a wasteful number, since it uses less digits than its factorization.

28389225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 378536 (or 378531 counting only the distinct ones).

The product of its digits is 69120, while the sum is 39.

The square root of 28389225 is about 5328.1539955223. The cubic root of 28389225 is about 305.0594706214.

The spelling of 28389225 in words is "twenty-eight million, three hundred eighty-nine thousand, two hundred twenty-five".