28528775 has 18 divisors (see below), whose sum is σ = 38888136. Its totient is φ = 20746000.

The previous prime is 28528751. The next prime is 28528781. The reversal of 28528775 is 57782582.

It is a de Polignac number, because none of the positive numbers 2^k-28528775 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1691 + ... + 7740.

It is an arithmetic number, because the mean of its divisors is an integer number (2160452).

Almost surely, 2^28528775 is an apocalyptic number.

28528775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

28528775 is a deficient number, since it is larger than the sum of its proper divisors (10359361).

28528775 is a wasteful number, since it uses less digits than its factorization.

28528775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9463 (or 9447 counting only the distinct ones).

The product of its digits is 313600, while the sum is 44.

The square root of 28528775 is about 5341.2334717741. The cubic root of 28528775 is about 305.5585036753.

The spelling of 28528775 in words is "twenty-eight million, five hundred twenty-eight thousand, seven hundred seventy-five".