133391 has 2 divisors, whose sum is σ = 133392. Its totient is φ = 133390.

The previous prime is 133387. The next prime is 133403. The reversal of 133391 is 193331.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 133391 - 2² = 133387 is a prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (133321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66695 + 66696.

It is an arithmetic number, because the mean of its divisors is an integer number (66696).

2¹³³³⁹¹ is an apocalyptic number.

133391 is a deficient number, since it is larger than the sum of its proper divisors (1).

133391 is an equidigital number, since it uses as much as digits as its factorization.

133391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 243, while the sum is 20.

The square root of 133391 is about 365.2273264694. The cubic root of 133391 is about 51.0946595165.

It can be divided in two parts, 133 and 391, that multiplied together give a triangular number (52003 = T₃₂₂).

The spelling of 133391 in words is "one hundred thirty-three thousand, three hundred ninety-one".