28528825 has 24 divisors (see below), whose sum is σ = 39044376. Its totient is φ = 20544000.

The previous prime is 28528807. The next prime is 28528831. The reversal of 28528825 is 52882582.

28528825 = T₁₁₉₀ + T₁₁₉₁ + ... + T₁₂₂₈.

It can be written as a sum of positive squares in 12 ways, for example, as 12616704 + 15912121 = 3552^2 + 3989^2 .

It is not a de Polignac number, because 28528825 - 2⁵ = 28528793 is a prime.

It is a Duffinian number.

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 23 ways as a sum of consecutive naturals, for example, 12255 + ... + 14395.

It is an arithmetic number, because the mean of its divisors is an integer number (1626849).

Almost surely, 2^28528825 is an apocalyptic number.

28528825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28528825 is a deficient number, since it is larger than the sum of its proper divisors (10515551).

28528825 is a wasteful number, since it uses less digits than its factorization.

28528825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2205 (or 2200 counting only the distinct ones).

The product of its digits is 102400, while the sum is 40.

The square root of 28528825 is about 5341.2381523388. The cubic root of 28528825 is about 305.5586821841.

The spelling of 28528825 in words is "twenty-eight million, five hundred twenty-eight thousand, eight hundred twenty-five".