257381 has 2 divisors, whose sum is σ = 257382. Its totient is φ = 257380.

The previous prime is 257371. The next prime is 257399. The reversal of 257381 is 183752.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 220900 + 36481 = 470^2 + 191^2 .

It is a cyclic number.

It is not a de Polignac number, because 257381 - 2¹⁴ = 240997 is a prime.

It is a super-2 number, since 2×257381² = 132489958322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 257381.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128690 + 128691.

It is an arithmetic number, because the mean of its divisors is an integer number (128691).

2²⁵⁷³⁸¹ is an apocalyptic number.

It is an amenable number.

257381 is a deficient number, since it is larger than the sum of its proper divisors (1).

257381 is an equidigital number, since it uses as much as digits as its factorization.

257381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1680, while the sum is 26.

The square root of 257381 is about 507.3273105205. The cubic root of 257381 is about 63.6100145089.

The spelling of 257381 in words is "two hundred fifty-seven thousand, three hundred eighty-one".