255989 has 2 divisors, whose sum is σ = 255990. Its totient is φ = 255988.

The previous prime is 255977. The next prime is 256019. The reversal of 255989 is 989552.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 209764 + 46225 = 458^2 + 215^2 .

It is a cyclic number.

It is not a de Polignac number, because 255989 - 2⁴ = 255973 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (255919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 127994 + 127995.

It is an arithmetic number, because the mean of its divisors is an integer number (127995).

2²⁵⁵⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

255989 is a deficient number, since it is larger than the sum of its proper divisors (1).

255989 is an equidigital number, since it uses as much as digits as its factorization.

255989 is an evil number, because the sum of its binary digits is even.

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

The square root of 255989 is about 505.9535551807. The cubic root of 255989 is about 63.4951326172.

The spelling of 255989 in words is "two hundred fifty-five thousand, nine hundred eighty-nine".