111813161 has 12 divisors (see below), whose sum is σ = 115105116. Its totient is φ = 108595200.

The previous prime is 111813137. The next prime is 111813173. The reversal of 111813161 is 161318111.

It can be written as a sum of positive squares in 6 ways, for example, as 6031936 + 105781225 = 2456^2 + 10285^2 .

It is a de Polignac number, because none of the positive numbers 2^k-111813161 is a prime.

It is a hoax number, since the sum of its digits (23) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111813101) 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 11 ways as a sum of consecutive naturals, for example, 989441 + ... + 989553.

It is an arithmetic number, because the mean of its divisors is an integer number (9592093).

Almost surely, 2^111813161 is an apocalyptic number.

It is an amenable number.

111813161 is a deficient number, since it is larger than the sum of its proper divisors (3291955).

111813161 is an equidigital number, since it uses as much as digits as its factorization.

111813161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 412 (or 311 counting only the distinct ones).

The product of its digits is 144, while the sum is 23.

The square root of 111813161 is about 10574.1742467202. The cubic root of 111813161 is about 481.7602628319.

The spelling of 111813161 in words is "one hundred eleven million, eight hundred thirteen thousand, one hundred sixty-one".