261101222101161 has 36 divisors (see below), whose sum is σ = 408437458311168. Its totient is φ = 160658645370912.

The previous prime is 261101222101063. The next prime is 261101222101201. The reversal of 261101222101161 is 161101222101162.

261101222101161 is a `hidden beast` number, since 2 + 611 + 0 + 1 + 2 + 22 + 10 + 1 + 16 + 1 = 666.

It is not a de Polignac number, because 261101222101161 - 2¹⁹ = 261101221576873 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261101222201161) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 2686636 + ... + 23009138.

It is an arithmetic number, because the mean of its divisors is an integer number (11345484953088).

Almost surely, 2^{261101222101161} is an apocalyptic number.

It is an amenable number.

261101222101161 is a deficient number, since it is larger than the sum of its proper divisors (147336236210007).

261101222101161 is a wasteful number, since it uses less digits than its factorization.

261101222101161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20330982 (or 20330966 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 27.

Subtracting from 261101222101161 its reverse (161101222101162), we obtain a palindrome (99999999999999).

The spelling of 261101222101161 in words is "two hundred sixty-one trillion, one hundred one billion, two hundred twenty-two million, one hundred one thousand, one hundred sixty-one".