257865329 has 2 divisors, whose sum is σ = 257865330. Its totient is φ = 257865328.

The previous prime is 257865271. The next prime is 257865331. The reversal of 257865329 is 923568752.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 216237025 + 41628304 = 14705^2 + 6452^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-257865329 is a prime.

It is a Sophie Germain prime.

Together with 257865331, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (257865389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128932664 + 128932665.

It is an arithmetic number, because the mean of its divisors is an integer number (128932665).

Almost surely, 2^257865329 is an apocalyptic number.

It is an amenable number.

257865329 is a deficient number, since it is larger than the sum of its proper divisors (1).

257865329 is an equidigital number, since it uses as much as digits as its factorization.

257865329 is an evil number, because the sum of its binary digits is even.

The product of its digits is 907200, while the sum is 47.

The square root of 257865329 is about 16058.1857318939. The cubic root of 257865329 is about 636.4988907924.

The spelling of 257865329 in words is "two hundred fifty-seven million, eight hundred sixty-five thousand, three hundred twenty-nine".