161115511161 has 16 divisors (see below), whose sum is σ = 234692985600. Its totient is φ = 97502784720.

The previous prime is 161115511127. The next prime is 161115511177.

It is a happy number.

161115511161 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 161115511161 - 2⁹ = 161115510649 is a prime.

It is a super-4 number, since 4×161115511161⁴ (a number of 46 digits) contains 4444 as substring.

It is not an unprimeable number, because it can be changed into a prime (161115511111) 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, 3551611 + ... + 3596688.

It is an arithmetic number, because the mean of its divisors is an integer number (14668311600).

Almost surely, 2^161115511161 is an apocalyptic number.

161115511161 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

161115511161 is a deficient number, since it is larger than the sum of its proper divisors (73577474439).

161115511161 is a wasteful number, since it uses less digits than its factorization.

161115511161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7148996.

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

It can be divided in two parts, 161115 and 511161, that added together give a palindrome (672276).

The spelling of 161115511161 in words is "one hundred sixty-one billion, one hundred fifteen million, five hundred eleven thousand, one hundred sixty-one".