28700257 has 2 divisors, whose sum is σ = 28700258. Its totient is φ = 28700256.

The previous prime is 28700249. The next prime is 28700311. The reversal of 28700257 is 75200782.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22268961 + 6431296 = 4719^2 + 2536^2 .

It is a cyclic number.

It is not a de Polignac number, because 28700257 - 2³ = 28700249 is a prime.

It is equal to p_1782274 and since 28700257 and 1782274 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (28700657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14350128 + 14350129.

It is an arithmetic number, because the mean of its divisors is an integer number (14350129).

Almost surely, 2^28700257 is an apocalyptic number.

It is an amenable number.

28700257 is a deficient number, since it is larger than the sum of its proper divisors (1).

28700257 is an equidigital number, since it uses as much as digits as its factorization.

28700257 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7840, while the sum is 31.

The square root of 28700257 is about 5357.2620805781. The cubic root of 28700257 is about 306.1695025416.

The spelling of 28700257 in words is "twenty-eight million, seven hundred thousand, two hundred fifty-seven".