133591 has 4 divisors (see below), whose sum is σ = 134992. Its totient is φ = 132192.

The previous prime is 133583. The next prime is 133597. The reversal of 133591 is 195331.

133591 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 195331 = 31 ⋅6301.

It is a cyclic number.

It is not a de Polignac number, because 133591 - 2³ = 133583 is a prime.

It is the 366-th Hogben number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133597) by changing a digit.

It is a nontrivial repunit in base 365.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 546 + ... + 751.

It is an arithmetic number, because the mean of its divisors is an integer number (33748).

2¹³³⁵⁹¹ is an apocalyptic number.

133591 is a deficient number, since it is larger than the sum of its proper divisors (1401).

133591 is a wasteful number, since it uses less digits than its factorization.

133591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1400.

The product of its digits is 405, while the sum is 22.

The square root of 133591 is about 365.5010259904. The cubic root of 133591 is about 51.1201830498.

The spelling of 133591 in words is "one hundred thirty-three thousand, five hundred ninety-one".