16161511161 has 4 divisors (see below), whose sum is σ = 21548681552. Its totient is φ = 10774340772.

The previous prime is 16161511153. The next prime is 16161511187. The reversal of 16161511161 is 16111516161.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 16161511161 - 2³ = 16161511153 is a prime.

It is a super-2 number, since 2×16161511161² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16161510161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2693585191 + ... + 2693585196.

It is an arithmetic number, because the mean of its divisors is an integer number (5387170388).

Almost surely, 2^16161511161 is an apocalyptic number.

It is an amenable number.

16161511161 is a deficient number, since it is larger than the sum of its proper divisors (5387170391).

16161511161 is an equidigital number, since it uses as much as digits as its factorization.

16161511161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5387170390.

The product of its digits is 1080, while the sum is 30.

Subtracting from 16161511161 its reverse (16111516161), we obtain a triangular number (49995000 = T₉₉₉₉).

The spelling of 16161511161 in words is "sixteen billion, one hundred sixty-one million, five hundred eleven thousand, one hundred sixty-one".