255517517 has 2 divisors, whose sum is σ = 255517518. Its totient is φ = 255517516.

The previous prime is 255517489. The next prime is 255517541. The reversal of 255517517 is 715715552.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 244421956 + 11095561 = 15634^2 + 3331^2 .

It is a cyclic number.

It is not a de Polignac number, because 255517517 - 2⁸ = 255517261 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (255517417) 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, 127758758 + 127758759.

It is an arithmetic number, because the mean of its divisors is an integer number (127758759).

Almost surely, 2^255517517 is an apocalyptic number.

It is an amenable number.

255517517 is a deficient number, since it is larger than the sum of its proper divisors (1).

255517517 is an equidigital number, since it uses as much as digits as its factorization.

255517517 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 61250, while the sum is 38.

The square root of 255517517 is about 15984.9152953652. The cubic root of 255517517 is about 634.5612667841.

The spelling of 255517517 in words is "two hundred fifty-five million, five hundred seventeen thousand, five hundred seventeen".