28253257 has 4 divisors (see below), whose sum is σ = 28324116. Its totient is φ = 28182400.

The previous prime is 28253233. The next prime is 28253261. The reversal of 28253257 is 75235282.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13995081 + 14258176 = 3741^2 + 3776^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28253257 is a prime.

It is a super-2 number, since 2×28253257² = 1596493062216098, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28253207) 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 3 ways as a sum of consecutive naturals, for example, 34828 + ... + 35629.

It is an arithmetic number, because the mean of its divisors is an integer number (7081029).

Almost surely, 2^28253257 is an apocalyptic number.

It is an amenable number.

28253257 is a deficient number, since it is larger than the sum of its proper divisors (70859).

28253257 is an equidigital number, since it uses as much as digits as its factorization.

28253257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70858.

The product of its digits is 33600, while the sum is 34.

The square root of 28253257 is about 5315.3792903235. The cubic root of 28253257 is about 304.5716714424.

The spelling of 28253257 in words is "twenty-eight million, two hundred fifty-three thousand, two hundred fifty-seven".