513668761 has 2 divisors, whose sum is σ = 513668762. Its totient is φ = 513668760.

The previous prime is 513668717. The next prime is 513668767. The reversal of 513668761 is 167866315.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 474368400 + 39300361 = 21780^2 + 6269^2 .

It is a cyclic number.

It is not a de Polignac number, because 513668761 - 2¹³ = 513660569 is a prime.

It is not a weakly prime, because it can be changed into another prime (513668767) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 256834380 + 256834381.

It is an arithmetic number, because the mean of its divisors is an integer number (256834381).

Almost surely, 2^513668761 is an apocalyptic number.

It is an amenable number.

513668761 is a deficient number, since it is larger than the sum of its proper divisors (1).

513668761 is an equidigital number, since it uses as much as digits as its factorization.

513668761 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 181440, while the sum is 43.

The square root of 513668761 is about 22664.2617572247. The cubic root of 513668761 is about 800.8682037910.

The spelling of 513668761 in words is "five hundred thirteen million, six hundred sixty-eight thousand, seven hundred sixty-one".