255439661 has 2 divisors, whose sum is σ = 255439662. Its totient is φ = 255439660.

The previous prime is 255439621. The next prime is 255439663. The reversal of 255439661 is 166934552.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 188101225 + 67338436 = 13715^2 + 8206^2 .

It is a cyclic number.

It is not a de Polignac number, because 255439661 - 2¹⁰ = 255438637 is a prime.

Together with 255439663, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (255439663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 127719830 + 127719831.

It is an arithmetic number, because the mean of its divisors is an integer number (127719831).

Almost surely, 2^255439661 is an apocalyptic number.

It is an amenable number.

255439661 is a deficient number, since it is larger than the sum of its proper divisors (1).

255439661 is an equidigital number, since it uses as much as digits as its factorization.

255439661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 194400, while the sum is 41.

The square root of 255439661 is about 15982.4798138462. The cubic root of 255439661 is about 634.4968101195.

The spelling of 255439661 in words is "two hundred fifty-five million, four hundred thirty-nine thousand, six hundred sixty-one".