257105 has 4 divisors (see below), whose sum is σ = 308532. Its totient is φ = 205680.

The previous prime is 257099. The next prime is 257107. The reversal of 257105 is 501752.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 124609 + 132496 = 353^2 + 364^2 .

It is a de Polignac number, because none of the positive numbers 2^k-257105 is a prime.

It is a super-2 number, since 2×257105² = 132205962050, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (257107) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25706 + ... + 25715.

It is an arithmetic number, because the mean of its divisors is an integer number (77133).

2²⁵⁷¹⁰⁵ is an apocalyptic number.

It is an amenable number.

257105 is a deficient number, since it is larger than the sum of its proper divisors (51427).

257105 is an equidigital number, since it uses as much as digits as its factorization.

257105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51426.

The product of its (nonzero) digits is 350, while the sum is 20.

The square root of 257105 is about 507.0552238169. The cubic root of 257105 is about 63.5872691842.

Adding to 257105 its reverse (501752), we get a palindrome (758857).

The spelling of 257105 in words is "two hundred fifty-seven thousand, one hundred five".