516785561 has 2 divisors, whose sum is σ = 516785562. Its totient is φ = 516785560.

The previous prime is 516785557. The next prime is 516785587. The reversal of 516785561 is 165587615.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 294328336 + 222457225 = 17156^2 + 14915^2 .

It is a cyclic number.

It is not a de Polignac number, because 516785561 - 2² = 516785557 is a prime.

It is not a weakly prime, because it can be changed into another prime (516785501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 258392780 + 258392781.

It is an arithmetic number, because the mean of its divisors is an integer number (258392781).

Almost surely, 2^516785561 is an apocalyptic number.

It is an amenable number.

516785561 is a deficient number, since it is larger than the sum of its proper divisors (1).

516785561 is an equidigital number, since it uses as much as digits as its factorization.

516785561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 252000, while the sum is 44.

The square root of 516785561 is about 22732.9180045150. The cubic root of 516785561 is about 802.4847541932.

The spelling of 516785561 in words is "five hundred sixteen million, seven hundred eighty-five thousand, five hundred sixty-one".