133831 has 2 divisors, whose sum is σ = 133832. Its totient is φ = 133830.

The previous prime is 133813. The next prime is 133843. The reversal of 133831 is 138331.

Together with previous prime (133813) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 133831 - 2⁹ = 133319 is a prime.

It is a super-2 number, since 2×133831² = 35821473122, which contains 22 as substring.

It is equal to p₁₂₄₈₄ and since 133831 and 12484 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 133799 and 133808.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (133801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66915 + 66916.

It is an arithmetic number, because the mean of its divisors is an integer number (66916).

2¹³³⁸³¹ is an apocalyptic number.

133831 is a deficient number, since it is larger than the sum of its proper divisors (1).

133831 is an equidigital number, since it uses as much as digits as its factorization.

133831 is an evil number, because the sum of its binary digits is even.

The product of its digits is 216, while the sum is 19.

The square root of 133831 is about 365.8291951171. The cubic root of 133831 is about 51.1507776860.

It can be divided in two parts, 1338 and 31, that added together give a square (1369 = 37²).

The spelling of 133831 in words is "one hundred thirty-three thousand, eight hundred thirty-one".