117181 has 8 divisors (see below), whose sum is σ = 127224. Its totient is φ = 107520.

The previous prime is 117167. The next prime is 117191. The reversal of 117181 is 181711.

117181 = T₂₇₈ + T₂₇₉ + T₂₈₀.

It can be written as a sum of positive squares in 4 ways, for example, as 900 + 116281 = 30^2 + 341^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a 5-Lehmer number, since φ(117181) divides (117181-1)⁵.

It is a cyclic number.

It is not a de Polignac number, because 117181 - 2⁷ = 117053 is a prime.

It is a super-2 number, since 2×117181² = 27462773522, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 7.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (117101) 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 7 ways as a sum of consecutive naturals, for example, 981 + ... + 1093.

It is an arithmetic number, because the mean of its divisors is an integer number (15903).

2¹¹⁷¹⁸¹ is an apocalyptic number.

117181 is the 280-th centered triangular number and also the 217-th centered pentagonal number.

It is an amenable number.

117181 is a deficient number, since it is larger than the sum of its proper divisors (10043).

117181 is a wasteful number, since it uses less digits than its factorization.

117181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191.

The product of its digits is 56, while the sum is 19.

The square root of 117181 is about 342.3171044514. The cubic root of 117181 is about 48.9349407285.

Adding to 117181 its reverse (181711), we get a palindrome (298892).

The spelling of 117181 in words is "one hundred seventeen thousand, one hundred eighty-one".