117811 has 2 divisors, whose sum is σ = 117812. Its totient is φ = 117810.

The previous prime is 117809. The next prime is 117833. The reversal of 117811 is 118711.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 117811 - 2¹ = 117809 is a prime.

Together with 117809, it forms a pair of twin primes.

117811 is a lucky number.

It is a zygodrome in base 2.

It is not a weakly prime, because it can be changed into another prime (117841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 58905 + 58906.

It is an arithmetic number, because the mean of its divisors is an integer number (58906).

2¹¹⁷⁸¹¹ is an apocalyptic number.

117811 is the 154-th centered decagonal number.

117811 is a deficient number, since it is larger than the sum of its proper divisors (1).

117811 is an equidigital number, since it uses as much as digits as its factorization.

117811 is an odious number, because the sum of its binary digits is odd.

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

The square root of 117811 is about 343.2360703656. The cubic root of 117811 is about 49.0224803138.

Subtracting 117811 from its reverse (118711), we obtain a square (900 = 30²).

The spelling of 117811 in words is "one hundred seventeen thousand, eight hundred eleven".