161511115161 has 32 divisors (see below), whose sum is σ = 248776541568. Its totient is φ = 92115645440.

The previous prime is 161511115151. The next prime is 161511115189.

It is a happy number.

161511115161 is nontrivially palindromic in base 10.

It is a cyclic number.

It is not a de Polignac number, because 161511115161 - 2⁷ = 161511115033 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161511115111) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6142735 + ... + 6168971.

It is an arithmetic number, because the mean of its divisors is an integer number (7774266924).

Almost surely, 2^161511115161 is an apocalyptic number.

161511115161 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

161511115161 is a deficient number, since it is larger than the sum of its proper divisors (87265426407).

161511115161 is a wasteful number, since it uses less digits than its factorization.

161511115161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37241.

The product of its digits is 900, while the sum is 30.

It can be divided in two parts, 161511 and 115161, that added together give a palindrome (276672).

The spelling of 161511115161 in words is "one hundred sixty-one billion, five hundred eleven million, one hundred fifteen thousand, one hundred sixty-one".