257609881 has 2 divisors, whose sum is σ = 257609882. Its totient is φ = 257609880.

The previous prime is 257609777. The next prime is 257609887. The reversal of 257609881 is 188906752.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 167055625 + 90554256 = 12925^2 + 9516^2 .

It is a cyclic number.

It is not a de Polignac number, because 257609881 - 2⁹ = 257609369 is a prime.

It is a super-2 number, since 2×257609881² = 132725701577668322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (257609887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128804940 + 128804941.

It is an arithmetic number, because the mean of its divisors is an integer number (128804941).

Almost surely, 2^257609881 is an apocalyptic number.

It is an amenable number.

257609881 is a deficient number, since it is larger than the sum of its proper divisors (1).

257609881 is an equidigital number, since it uses as much as digits as its factorization.

257609881 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 241920, while the sum is 46.

The square root of 257609881 is about 16050.2299360476. The cubic root of 257609881 is about 636.2886439835.

The spelling of 257609881 in words is "two hundred fifty-seven million, six hundred nine thousand, eight hundred eighty-one".