28508185 has 4 divisors (see below), whose sum is σ = 34209828. Its totient is φ = 22806544.

The previous prime is 28508171. The next prime is 28508191. The reversal of 28508185 is 58180582.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 58180582 = 2 ⋅29090291.

It can be written as a sum of positive squares in 2 ways, for example, as 7246864 + 21261321 = 2692^2 + 4611^2 .

It is a cyclic number.

It is not a de Polignac number, because 28508185 - 2⁵ = 28508153 is a prime.

It is a super-2 number, since 2×28508185² = 1625433223988450, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2850814 + ... + 2850823.

It is an arithmetic number, because the mean of its divisors is an integer number (8552457).

Almost surely, 2^28508185 is an apocalyptic number.

It is an amenable number.

28508185 is a deficient number, since it is larger than the sum of its proper divisors (5701643).

28508185 is an equidigital number, since it uses as much as digits as its factorization.

28508185 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5701642.

The product of its (nonzero) digits is 25600, while the sum is 37.

The square root of 28508185 is about 5339.3056664701. The cubic root of 28508185 is about 305.4849759970.

The spelling of 28508185 in words is "twenty-eight million, five hundred eight thousand, one hundred eighty-five".