28505228 has 12 divisors (see below), whose sum is σ = 50351112. Its totient is φ = 14119200.

The previous prime is 28505219. The next prime is 28505237. The reversal of 28505228 is 82250582.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (28505219) and next prime (28505237).

It is a junction number, because it is equal to n+sod(n) for n = 28505194 and 28505203.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 32873 + ... + 33728.

It is an arithmetic number, because the mean of its divisors is an integer number (4195926).

Almost surely, 2^28505228 is an apocalyptic number.

It is an amenable number.

28505228 is a deficient number, since it is larger than the sum of its proper divisors (21845884).

28505228 is a wasteful number, since it uses less digits than its factorization.

28505228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66712 (or 66710 counting only the distinct ones).

The product of its (nonzero) digits is 12800, while the sum is 32.

The square root of 28505228 is about 5339.0287506250. The cubic root of 28505228 is about 305.4744135298.

The spelling of 28505228 in words is "twenty-eight million, five hundred five thousand, two hundred twenty-eight".