257998 has 8 divisors (see below), whose sum is σ = 416808. Its totient is φ = 119064.

The previous prime is 257993. The next prime is 258019. The reversal of 257998 is 899752.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 257998.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257993) by changing a digit.

257998 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 in 3 ways as a sum of consecutive naturals, for example, 4936 + ... + 4987.

It is an arithmetic number, because the mean of its divisors is an integer number (52101).

2²⁵⁷⁹⁹⁸ is an apocalyptic number.

257998 is a deficient number, since it is larger than the sum of its proper divisors (158810).

257998 is a wasteful number, since it uses less digits than its factorization.

257998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9938.

The product of its digits is 45360, while the sum is 40.

The square root of 257998 is about 507.9350352161. The cubic root of 257998 is about 63.6608031051.

The spelling of 257998 in words is "two hundred fifty-seven thousand, nine hundred ninety-eight".