257525381 has 2 divisors, whose sum is σ = 257525382. Its totient is φ = 257525380.

The previous prime is 257525351. The next prime is 257525399. The reversal of 257525381 is 183525752.

257525381 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., 154604356 + 102921025 = 12434^2 + 10145^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-257525381 is a prime.

It is a super-2 number, since 2×257525381² = 132638643718390322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257525321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128762690 + 128762691.

It is an arithmetic number, because the mean of its divisors is an integer number (128762691).

Almost surely, 2^257525381 is an apocalyptic number.

It is an amenable number.

257525381 is a deficient number, since it is larger than the sum of its proper divisors (1).

257525381 is an equidigital number, since it uses as much as digits as its factorization.

257525381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 84000, while the sum is 38.

The square root of 257525381 is about 16047.5973591064. The cubic root of 257525381 is about 636.2190655574.

The spelling of 257525381 in words is "two hundred fifty-seven million, five hundred twenty-five thousand, three hundred eighty-one".