161111 has 4 divisors (see below), whose sum is σ = 163392. Its totient is φ = 158832.

The previous prime is 161093. The next prime is 161123. The reversal of 161111 is 111161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 111161 = 89 ⋅1249.

It is a cyclic number.

It is not a de Polignac number, because 161111 - 2⁶ = 161047 is a prime.

It is a Duffinian number.

161111 is a modest number, since divided by 1111 gives 16 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 161092 and 161101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1031 + ... + 1176.

It is an arithmetic number, because the mean of its divisors is an integer number (40848).

2¹⁶¹¹¹¹ is an apocalyptic number.

161111 is a deficient number, since it is larger than the sum of its proper divisors (2281).

161111 is an equidigital number, since it uses as much as digits as its factorization.

161111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2280.

The product of its digits is 6, while the sum is 11.

The square root of 161111 is about 401.3863475506. The cubic root of 161111 is about 54.4137175254.

Adding to 161111 its reverse (111161), we get a palindrome (272272).

It can be divided in two parts, 161 and 111, that multiplied together give a palindrome (17871).

The spelling of 161111 in words is "one hundred sixty-one thousand, one hundred eleven".