28072525 has 24 divisors (see below), whose sum is σ = 39700584. Its totient is φ = 19507200.

The previous prime is 28072523. The next prime is 28072549. The reversal of 28072525 is 52527082.

28072525 = 3746² + 3747².

It can be written as a sum of positive squares in 12 ways, for example, as 14032516 + 14040009 = 3746^2 + 3747^2 .

It is not a de Polignac number, because 28072525 - 2¹ = 28072523 is a prime.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28072523) by changing a digit.

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, 2985 + ... + 8065.

It is an arithmetic number, because the mean of its divisors is an integer number (1654191).

Almost surely, 2^28072525 is an apocalyptic number.

28072525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

28072525 is the 3747-th centered square number.

It is an amenable number.

28072525 is a deficient number, since it is larger than the sum of its proper divisors (11628059).

28072525 is a wasteful number, since it uses less digits than its factorization.

28072525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5121 (or 5116 counting only the distinct ones).

The product of its (nonzero) digits is 11200, while the sum is 31.

The square root of 28072525 is about 5298.3511586153. The cubic root of 28072525 is about 303.9208480739.

The spelling of 28072525 in words is "twenty-eight million, seventy-two thousand, five hundred twenty-five".