118181 has 4 divisors (see below), whose sum is σ = 135072. Its totient is φ = 101292.

The previous prime is 118171. The next prime is 118189. The reversal of 118181 is 181811.

118181 is nontrivially palindromic in base 12.

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 a cyclic number.

It is not a de Polignac number, because 118181 - 2¹⁴ = 101797 is a prime.

It is a super-2 number, since 2×118181² = 27933497522, which contains 22 as substring.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 118181.

It is not an unprimeable number, because it can be changed into a prime (118189) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8435 + ... + 8448.

It is an arithmetic number, because the mean of its divisors is an integer number (33768).

2¹¹⁸¹⁸¹ is an apocalyptic number.

It is an amenable number.

118181 is a deficient number, since it is larger than the sum of its proper divisors (16891).

118181 is an equidigital number, since it uses as much as digits as its factorization.

118181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16890.

The product of its digits is 64, while the sum is 20.

The square root of 118181 is about 343.7746354809. The cubic root of 118181 is about 49.0737470665.

Adding to 118181 its reverse (181811), we get a palindrome (299992).

It can be divided in two parts, 11 and 8181, that added together give a 13-th power (8192 = 2¹³).

The spelling of 118181 in words is "one hundred eighteen thousand, one hundred eighty-one".