257128 has 8 divisors (see below), whose sum is σ = 482130. Its totient is φ = 128560.

The previous prime is 257123. The next prime is 257141. The reversal of 257128 is 821752.

It can be written as a sum of positive squares in only one way, i.e., 142884 + 114244 = 378^2 + 338^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×257128² = 132229616768, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (257123) by changing a digit.

257128 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16063 + ... + 16078.

2²⁵⁷¹²⁸ is an apocalyptic number.

It is an amenable number.

257128 is a deficient number, since it is larger than the sum of its proper divisors (225002).

257128 is a wasteful number, since it uses less digits than its factorization.

257128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32147 (or 32143 counting only the distinct ones).

The product of its digits is 1120, while the sum is 25.

The square root of 257128 is about 507.0779032851. The cubic root of 257128 is about 63.5891652495.

It can be divided in two parts, 257 and 128, that multiplied together give a triangular number (32896 = T₂₅₆).

The spelling of 257128 in words is "two hundred fifty-seven thousand, one hundred twenty-eight".