28517905 has 12 divisors (see below), whose sum is σ = 37057500. Its totient is φ = 21058752.

The previous prime is 28517899. The next prime is 28517911. The reversal of 28517905 is 50971582.

It is an interprime number because it is at equal distance from previous prime (28517899) and next prime (28517911).

It can be written as a sum of positive squares in 6 ways, for example, as 1185921 + 27331984 = 1089^2 + 5228^2 .

It is not a de Polignac number, because 28517905 - 2³ = 28517897 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16030 + ... + 17719.

It is an arithmetic number, because the mean of its divisors is an integer number (3088125).

Almost surely, 2^28517905 is an apocalyptic number.

It is an amenable number.

28517905 is a deficient number, since it is larger than the sum of its proper divisors (8539595).

28517905 is a wasteful number, since it uses less digits than its factorization.

28517905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33780 (or 33767 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 37.

The square root of 28517905 is about 5340.2158196088. The cubic root of 28517905 is about 305.5196908992.

The spelling of 28517905 in words is "twenty-eight million, five hundred seventeen thousand, nine hundred five".