255961 has 2 divisors, whose sum is σ = 255962. Its totient is φ = 255960.

The previous prime is 255947. The next prime is 255971. The reversal of 255961 is 169552.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 235225 + 20736 = 485^2 + 144^2 .

It is a cyclic number.

It is not a de Polignac number, because 255961 - 2¹³ = 247769 is a prime.

255961 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (255971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 127980 + 127981.

It is an arithmetic number, because the mean of its divisors is an integer number (127981).

2²⁵⁵⁹⁶¹ is an apocalyptic number.

It is an amenable number.

255961 is a deficient number, since it is larger than the sum of its proper divisors (1).

255961 is an equidigital number, since it uses as much as digits as its factorization.

255961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2700, while the sum is 28.

The square root of 255961 is about 505.9258839000. The cubic root of 255961 is about 63.4928175066.

The spelling of 255961 in words is "two hundred fifty-five thousand, nine hundred sixty-one".