25961611961 has 2 divisors, whose sum is σ = 25961611962. Its totient is φ = 25961611960.

The previous prime is 25961611903. The next prime is 25961612041. The reversal of 25961611961 is 16911616952.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16446780025 + 9514831936 = 128245^2 + 97544^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25961611961 is a prime.

It is a super-3 number, since 3×25961611961³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (25961611901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12980805980 + 12980805981.

It is an arithmetic number, because the mean of its divisors is an integer number (12980805981).

Almost surely, 2^25961611961 is an apocalyptic number.

It is an amenable number.

25961611961 is a deficient number, since it is larger than the sum of its proper divisors (1).

25961611961 is an equidigital number, since it uses as much as digits as its factorization.

25961611961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 174960, while the sum is 47.

The spelling of 25961611961 in words is "twenty-five billion, nine hundred sixty-one million, six hundred eleven thousand, nine hundred sixty-one".