257155317 has 20 divisors (see below), whose sum is σ = 384896160. Its totient is φ = 171102024.

The previous prime is 257155309. The next prime is 257155357. The reversal of 257155317 is 713551752.

It is a happy number.

257155317 is a `hidden beast` number, since 2 + 571 + 55 + 31 + 7 = 666.

It is not a de Polignac number, because 257155317 - 2³ = 257155309 is a prime.

It is a super-2 number, since 2×257155317² = 132257714122740978, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257155357) 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 in 19 ways as a sum of consecutive naturals, for example, 42784 + ... + 48422.

It is an arithmetic number, because the mean of its divisors is an integer number (19244808).

Almost surely, 2^257155317 is an apocalyptic number.

257155317 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

257155317 is a deficient number, since it is larger than the sum of its proper divisors (127740843).

257155317 is an equidigital number, since it uses as much as digits as its factorization.

257155317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6214 (or 6205 counting only the distinct ones).

The product of its digits is 36750, while the sum is 36.

The square root of 257155317 is about 16036.0630143436. The cubic root of 257155317 is about 635.9141705109.

The spelling of 257155317 in words is "two hundred fifty-seven million, one hundred fifty-five thousand, three hundred seventeen".