133909 has 4 divisors (see below), whose sum is σ = 141804. Its totient is φ = 126016.

The previous prime is 133877. The next prime is 133919. The reversal of 133909 is 909331.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 61009 + 72900 = 247^2 + 270^2 .

It is a cyclic number.

It is not a de Polignac number, because 133909 - 2⁵ = 133877 is a prime.

It is an Ulam 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 (133919) 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 in 3 ways as a sum of consecutive naturals, for example, 3922 + ... + 3955.

It is an arithmetic number, because the mean of its divisors is an integer number (35451).

2¹³³⁹⁰⁹ is an apocalyptic number.

It is an amenable number.

133909 is a deficient number, since it is larger than the sum of its proper divisors (7895).

133909 is an equidigital number, since it uses as much as digits as its factorization.

133909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7894.

The product of its (nonzero) digits is 729, while the sum is 25.

The square root of 133909 is about 365.9357867167. The cubic root of 133909 is about 51.1607130667.

The spelling of 133909 in words is "one hundred thirty-three thousand, nine hundred nine".