255999999989 has 2 divisors, whose sum is σ = 255999999990. Its totient is φ = 255999999988.

The previous prime is 255999999943. The next prime is 256000000007. The reversal of 255999999989 is 989999999552.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 159252874225 + 96747125764 = 399065^2 + 311042^2 .

It is a cyclic number.

It is not a de Polignac number, because 255999999989 - 2²⁰ = 255998951413 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 255999999898 and 255999999907.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (255999999919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 127999999994 + 127999999995.

It is an arithmetic number, because the mean of its divisors is an integer number (127999999995).

Almost surely, 2^255999999989 is an apocalyptic number.

It is an amenable number.

255999999989 is a deficient number, since it is larger than the sum of its proper divisors (1).

255999999989 is an equidigital number, since it uses as much as digits as its factorization.

255999999989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17218688400, while the sum is 92.

The spelling of 255999999989 in words is "two hundred fifty-five billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred eighty-nine".