181561413611 has 2 divisors, whose sum is σ = 181561413612. Its totient is φ = 181561413610.

The previous prime is 181561413581. The next prime is 181561413623. The reversal of 181561413611 is 116314165181.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 181561413611 - 2²² = 181557219307 is a prime.

It is not a weakly prime, because it can be changed into another prime (181561416611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90780706805 + 90780706806.

It is an arithmetic number, because the mean of its divisors is an integer number (90780706806).

Almost surely, 2^181561413611 is an apocalyptic number.

181561413611 is a deficient number, since it is larger than the sum of its proper divisors (1).

181561413611 is an equidigital number, since it uses as much as digits as its factorization.

181561413611 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17280, while the sum is 38.

Adding to 181561413611 its reverse (116314165181), we get a palindrome (297875578792).

The spelling of 181561413611 in words is "one hundred eighty-one billion, five hundred sixty-one million, four hundred thirteen thousand, six hundred eleven".