257985 has 60 divisors (see below), whose sum is σ = 579348. Its totient is φ = 108864.

The previous prime is 257981. The next prime is 257987. The reversal of 257985 is 589752.

257985 is a `hidden beast` number, since 2 + 579 + 85 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 63504 + 194481 = 252^2 + 441^2 .

It is not a de Polignac number, because 257985 - 2² = 257981 is a prime.

Its product of digits (25200) is a multiple of the sum of its prime divisors (28).

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257981) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 19839 + ... + 19851.

257985 is a Friedman number, since it can be written as 585*9*7^2, using all its digits and the basic arithmetic operations.

2²⁵⁷⁹⁸⁵ is an apocalyptic number.

It is an amenable number.

257985 is an abundant number, since it is smaller than the sum of its proper divisors (321363).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

257985 is a wasteful number, since it uses less digits than its factorization.

257985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44 (or 28 counting only the distinct ones).

The product of its digits is 25200, while the sum is 36.

The square root of 257985 is about 507.9222381428. The cubic root of 257985 is about 63.6597338406.

The spelling of 257985 in words is "two hundred fifty-seven thousand, nine hundred eighty-five".