28172457 has 12 divisors (see below), whose sum is σ = 41089984. Its totient is φ = 18598680.

The previous prime is 28172449. The next prime is 28172461. The reversal of 28172457 is 75427182.

It is not a de Polignac number, because 28172457 - 2³ = 28172449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28172407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14269 + ... + 16122.

Almost surely, 2^28172457 is an apocalyptic number.

It is an amenable number.

28172457 is a deficient number, since it is larger than the sum of its proper divisors (12917527).

28172457 is a wasteful number, since it uses less digits than its factorization.

28172457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30500 (or 30497 counting only the distinct ones).

The product of its digits is 31360, while the sum is 36.

The square root of 28172457 is about 5307.7732619244. The cubic root of 28172457 is about 304.2810514017.

The spelling of 28172457 in words is "twenty-eight million, one hundred seventy-two thousand, four hundred fifty-seven".