28457257 has 2 divisors, whose sum is σ = 28457258. Its totient is φ = 28457256.

The previous prime is 28457249. The next prime is 28457263. The reversal of 28457257 is 75275482.

It is a happy number.

28457257 is nontrivially palindromic in base 8.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25512601 + 2944656 = 5051^2 + 1716^2 .

It is a cyclic number.

It is not a de Polignac number, because 28457257 - 2³ = 28457249 is a prime.

It is not a weakly prime, because it can be changed into another prime (28457227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14228628 + 14228629.

It is an arithmetic number, because the mean of its divisors is an integer number (14228629).

Almost surely, 2^28457257 is an apocalyptic number.

It is an amenable number.

28457257 is a deficient number, since it is larger than the sum of its proper divisors (1).

28457257 is an equidigital number, since it uses as much as digits as its factorization.

28457257 is an evil number, because the sum of its binary digits is even.

The product of its digits is 156800, while the sum is 40.

The square root of 28457257 is about 5334.5343751821. The cubic root of 28457257 is about 305.3029579513.

The spelling of 28457257 in words is "twenty-eight million, four hundred fifty-seven thousand, two hundred fifty-seven".