28305975 has 24 divisors (see below), whose sum is σ = 47688912. Its totient is φ = 14809600.

The previous prime is 28305971. The next prime is 28305983. The reversal of 28305975 is 57950382.

It is not a de Polignac number, because 28305975 - 2² = 28305971 is a prime.

It is a super-3 number, since 3×28305975³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28305971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 415 + ... + 7535.

It is an arithmetic number, because the mean of its divisors is an integer number (1987038).

Almost surely, 2^28305975 is an apocalyptic number.

28305975 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

28305975 is a deficient number, since it is larger than the sum of its proper divisors (19382937).

28305975 is a wasteful number, since it uses less digits than its factorization.

28305975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7187 (or 7182 counting only the distinct ones).

The product of its (nonzero) digits is 75600, while the sum is 39.

The square root of 28305975 is about 5320.3359856310. The cubic root of 28305975 is about 304.7609880595.

The spelling of 28305975 in words is "twenty-eight million, three hundred five thousand, nine hundred seventy-five".