257281 has 2 divisors, whose sum is σ = 257282. Its totient is φ = 257280.

The previous prime is 257273. The next prime is 257287. The reversal of 257281 is 182752.

257281 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 167281 + 90000 = 409^2 + 300^2 .

It is a cyclic number.

It is not a de Polignac number, because 257281 - 2³ = 257273 is a prime.

It is a super-2 number, since 2×257281² = 132387025922, which contains 22 as substring.

257281 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (257287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128640 + 128641.

It is an arithmetic number, because the mean of its divisors is an integer number (128641).

2²⁵⁷²⁸¹ is an apocalyptic number.

It is an amenable number.

257281 is a deficient number, since it is larger than the sum of its proper divisors (1).

257281 is an equidigital number, since it uses as much as digits as its factorization.

257281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1120, while the sum is 25.

The square root of 257281 is about 507.2287452422. The cubic root of 257281 is about 63.6017753285.

Subtracting from 257281 its reverse (182752), we obtain a square (74529 = 273²).

The spelling of 257281 in words is "two hundred fifty-seven thousand, two hundred eighty-one".