25697776613 has 2 divisors, whose sum is σ = 25697776614. Its totient is φ = 25697776612.

The previous prime is 25697776597. The next prime is 25697776627. The reversal of 25697776613 is 31667779652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19483134724 + 6214641889 = 139582^2 + 78833^2 .

It is a cyclic number.

It is not a de Polignac number, because 25697776613 - 2⁴ = 25697776597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25697776673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12848888306 + 12848888307.

It is an arithmetic number, because the mean of its divisors is an integer number (12848888307).

Almost surely, 2^25697776613 is an apocalyptic number.

It is an amenable number.

25697776613 is a deficient number, since it is larger than the sum of its proper divisors (1).

25697776613 is an equidigital number, since it uses as much as digits as its factorization.

25697776613 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20003760, while the sum is 59.

The spelling of 25697776613 in words is "twenty-five billion, six hundred ninety-seven million, seven hundred seventy-six thousand, six hundred thirteen".