28528815 has 16 divisors (see below), whose sum is σ = 52167168. Its totient is φ = 13041696.

The previous prime is 28528807. The next prime is 28528831. The reversal of 28528815 is 51882582.

28528815 = 1421² + 1422² + ... + 1434².

It is not a de Polignac number, because 28528815 - 2³ = 28528807 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 135747 + ... + 135956.

It is an arithmetic number, because the mean of its divisors is an integer number (3260448).

Almost surely, 2^28528815 is an apocalyptic number.

28528815 is a deficient number, since it is larger than the sum of its proper divisors (23638353).

28528815 is a wasteful number, since it uses less digits than its factorization.

28528815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 271718.

The product of its digits is 51200, while the sum is 39.

The square root of 28528815 is about 5341.2372162262. The cubic root of 28528815 is about 305.5586464824.

The spelling of 28528815 in words is "twenty-eight million, five hundred twenty-eight thousand, eight hundred fifteen".