133811 has 2 divisors, whose sum is σ = 133812. Its totient is φ = 133810.

The previous prime is 133801. The next prime is 133813. The reversal of 133811 is 118331.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 133811 - 2¹⁴ = 117427 is a prime.

Together with 133813, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p₁₂₄₈₂ and since 133811 and 12482 have the same sum of digits, it is a Honaker prime.

It is a plaindrome in base 9 and base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 133811.

It is not a weakly prime, because it can be changed into another prime (133813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66905 + 66906.

It is an arithmetic number, because the mean of its divisors is an integer number (66906).

2¹³³⁸¹¹ is an apocalyptic number.

133811 is a deficient number, since it is larger than the sum of its proper divisors (1).

133811 is an equidigital number, since it uses as much as digits as its factorization.

133811 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72, while the sum is 17.

The square root of 133811 is about 365.8018589346. The cubic root of 133811 is about 51.1482295307.

The spelling of 133811 in words is "one hundred thirty-three thousand, eight hundred eleven".