181561413601 has 16 divisors (see below), whose sum is σ = 197031320640. Its totient is φ = 166627985920.

The previous prime is 181561413581. The next prime is 181561413611. The reversal of 181561413601 is 106314165181.

It is a cyclic number.

It is not a de Polignac number, because 181561413601 - 2³⁵ = 147201675233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (181561413611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1313550 + ... + 1445176.

It is an arithmetic number, because the mean of its divisors is an integer number (12314457540).

Almost surely, 2^181561413601 is an apocalyptic number.

It is an amenable number.

181561413601 is a deficient number, since it is larger than the sum of its proper divisors (15469907039).

181561413601 is a wasteful number, since it uses less digits than its factorization.

181561413601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133664.

The product of its (nonzero) digits is 17280, while the sum is 37.

Adding to 181561413601 its reverse (106314165181), we get a palindrome (287875578782).

The spelling of 181561413601 in words is "one hundred eighty-one billion, five hundred sixty-one million, four hundred thirteen thousand, six hundred one".