257861657 has 2 divisors, whose sum is σ = 257861658. Its totient is φ = 257861656.

The previous prime is 257861629. The next prime is 257861663. The reversal of 257861657 is 756168752.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 214446736 + 43414921 = 14644^2 + 6589^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-257861657 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (257861677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128930828 + 128930829.

It is an arithmetic number, because the mean of its divisors is an integer number (128930829).

Almost surely, 2^257861657 is an apocalyptic number.

It is an amenable number.

257861657 is a deficient number, since it is larger than the sum of its proper divisors (1).

257861657 is an equidigital number, since it uses as much as digits as its factorization.

257861657 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 705600, while the sum is 47.

The square root of 257861657 is about 16058.0713972756. The cubic root of 257861657 is about 636.4958695318.

The spelling of 257861657 in words is "two hundred fifty-seven million, eight hundred sixty-one thousand, six hundred fifty-seven".