255998 has 8 divisors (see below), whose sum is σ = 396480. Its totient is φ = 123840.

The previous prime is 255989. The next prime is 256019. The reversal of 255998 is 899552.

It is a happy number.

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

It is an Ulam number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2003 + ... + 2126.

It is an arithmetic number, because the mean of its divisors is an integer number (49560).

2²⁵⁵⁹⁹⁸ is an apocalyptic number.

255998 is a deficient number, since it is larger than the sum of its proper divisors (140482).

255998 is a wasteful number, since it uses less digits than its factorization.

255998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4162.

The product of its digits is 32400, while the sum is 38.

The square root of 255998 is about 505.9624491995. The cubic root of 255998 is about 63.4958767240.

Adding to 255998 its sum of digits (38), we get a square (256036 = 506²).

The spelling of 255998 in words is "two hundred fifty-five thousand, nine hundred ninety-eight".