25506116161 has 2 divisors, whose sum is σ = 25506116162. Its totient is φ = 25506116160.

The previous prime is 25506116159. The next prime is 25506116191. The reversal of 25506116161 is 16161160552.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16629649936 + 8876466225 = 128956^2 + 94215^2 .

It is a cyclic number.

It is not a de Polignac number, because 25506116161 - 2¹ = 25506116159 is a prime.

Together with 25506116159, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (25506116101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12753058080 + 12753058081.

It is an arithmetic number, because the mean of its divisors is an integer number (12753058081).

Almost surely, 2^25506116161 is an apocalyptic number.

It is an amenable number.

25506116161 is a deficient number, since it is larger than the sum of its proper divisors (1).

25506116161 is an equidigital number, since it uses as much as digits as its factorization.

25506116161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10800, while the sum is 34.

The spelling of 25506116161 in words is "twenty-five billion, five hundred six million, one hundred sixteen thousand, one hundred sixty-one".