2661256515913 has 2 divisors, whose sum is σ = 2661256515914. Its totient is φ = 2661256515912.

The previous prime is 2661256515901. The next prime is 2661256515917. The reversal of 2661256515913 is 3195156521662.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2651045009209 + 10211506704 = 1628203^2 + 101052^2 .

It is a cyclic number.

It is not a de Polignac number, because 2661256515913 - 2⁵ = 2661256515881 is a prime.

It is not a weakly prime, because it can be changed into another prime (2661256515917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1330628257956 + 1330628257957.

It is an arithmetic number, because the mean of its divisors is an integer number (1330628257957).

Almost surely, 2^{2661256515913} is an apocalyptic number.

It is an amenable number.

2661256515913 is a deficient number, since it is larger than the sum of its proper divisors (1).

2661256515913 is an equidigital number, since it uses as much as digits as its factorization.

2661256515913 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2916000, while the sum is 52.

The spelling of 2661256515913 in words is "two trillion, six hundred sixty-one billion, two hundred fifty-six million, five hundred fifteen thousand, nine hundred thirteen".