28157265 has 24 divisors (see below), whose sum is σ = 49089768. Its totient is φ = 14929920.

The previous prime is 28157263. The next prime is 28157273. The reversal of 28157265 is 56275182.

It is a happy number.

28157265 is a `hidden beast` number, since 2 + 81 + 572 + 6 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 3326976 + 24830289 = 1824^2 + 4983^2 .

It is not a de Polignac number, because 28157265 - 2¹ = 28157263 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28157263) 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, 6417 + ... + 9873.

It is an arithmetic number, because the mean of its divisors is an integer number (2045407).

Almost surely, 2^28157265 is an apocalyptic number.

It is an amenable number.

28157265 is a deficient number, since it is larger than the sum of its proper divisors (20932503).

28157265 is a wasteful number, since it uses less digits than its factorization.

28157265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3649 (or 3646 counting only the distinct ones).

The product of its digits is 33600, while the sum is 36.

The square root of 28157265 is about 5306.3419603339. The cubic root of 28157265 is about 304.2263470392.

The spelling of 28157265 in words is "twenty-eight million, one hundred fifty-seven thousand, two hundred sixty-five".