515791957861 has 2 divisors, whose sum is σ = 515791957862. Its totient is φ = 515791957860.

The previous prime is 515791957859. The next prime is 515791957909. The reversal of 515791957861 is 168759197515.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 258216422500 + 257575535361 = 508150^2 + 507519^2 .

It is a cyclic number.

It is not a de Polignac number, because 515791957861 - 2¹ = 515791957859 is a prime.

Together with 515791957859, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 515791957793 and 515791957802.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (515791957841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 257895978930 + 257895978931.

It is an arithmetic number, because the mean of its divisors is an integer number (257895978931).

Almost surely, 2^515791957861 is an apocalyptic number.

It is an amenable number.

515791957861 is a deficient number, since it is larger than the sum of its proper divisors (1).

515791957861 is an equidigital number, since it uses as much as digits as its factorization.

515791957861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23814000, while the sum is 64.

The spelling of 515791957861 in words is "five hundred fifteen billion, seven hundred ninety-one million, nine hundred fifty-seven thousand, eight hundred sixty-one".