257087381 has 2 divisors, whose sum is σ = 257087382. Its totient is φ = 257087380.

The previous prime is 257087351. The next prime is 257087393. The reversal of 257087381 is 183780752.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 238208356 + 18879025 = 15434^2 + 4345^2 .

It is a cyclic number.

It is not a de Polignac number, because 257087381 - 2²² = 252893077 is a prime.

It is a super-2 number, since 2×257087381² = 132187842938878322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257087351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128543690 + 128543691.

It is an arithmetic number, because the mean of its divisors is an integer number (128543691).

Almost surely, 2^257087381 is an apocalyptic number.

It is an amenable number.

257087381 is a deficient number, since it is larger than the sum of its proper divisors (1).

257087381 is an equidigital number, since it uses as much as digits as its factorization.

257087381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 94080, while the sum is 41.

The square root of 257087381 is about 16033.9446487756. The cubic root of 257087381 is about 635.8581663931.

The spelling of 257087381 in words is "two hundred fifty-seven million, eighty-seven thousand, three hundred eighty-one".