505255561 has 2 divisors, whose sum is σ = 505255562. Its totient is φ = 505255560.

The previous prime is 505255537. The next prime is 505255567. The reversal of 505255561 is 165552505.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 415385161 + 89870400 = 20381^2 + 9480^2 .

It is a cyclic number.

It is not a de Polignac number, because 505255561 - 2¹⁷ = 505124489 is a prime.

It is not a weakly prime, because it can be changed into another prime (505255567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 252627780 + 252627781.

It is an arithmetic number, because the mean of its divisors is an integer number (252627781).

Almost surely, 2^505255561 is an apocalyptic number.

It is an amenable number.

505255561 is a deficient number, since it is larger than the sum of its proper divisors (1).

505255561 is an equidigital number, since it uses as much as digits as its factorization.

505255561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 37500, while the sum is 34.

The square root of 505255561 is about 22477.8904926597. The cubic root of 505255561 is about 796.4717333988.

The spelling of 505255561 in words is "five hundred five million, two hundred fifty-five thousand, five hundred sixty-one".