25917765961 has 2 divisors, whose sum is σ = 25917765962. Its totient is φ = 25917765960.

The previous prime is 25917765941. The next prime is 25917765967. The reversal of 25917765961 is 16956771952.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13258140736 + 12659625225 = 115144^2 + 112515^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25917765961 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 25917765896 and 25917765905.

It is not a weakly prime, because it can be changed into another prime (25917765967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12958882980 + 12958882981.

It is an arithmetic number, because the mean of its divisors is an integer number (12958882981).

Almost surely, 2^25917765961 is an apocalyptic number.

It is an amenable number.

25917765961 is a deficient number, since it is larger than the sum of its proper divisors (1).

25917765961 is an equidigital number, since it uses as much as digits as its factorization.

25917765961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7144200, while the sum is 58.

The spelling of 25917765961 in words is "twenty-five billion, nine hundred seventeen million, seven hundred sixty-five thousand, nine hundred sixty-one".