133409 has 4 divisors (see below), whose sum is σ = 135360. Its totient is φ = 131460.

The previous prime is 133403. The next prime is 133417. The reversal of 133409 is 904331.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 904331 = 97 ⋅9323.

It is a cyclic number.

It is not a de Polignac number, because 133409 - 2⁸ = 133153 is a prime.

It is a super-2 number, since 2×133409² = 35595922562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (133403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 869 + ... + 1010.

It is an arithmetic number, because the mean of its divisors is an integer number (33840).

2¹³³⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

133409 is a deficient number, since it is larger than the sum of its proper divisors (1951).

133409 is an equidigital number, since it uses as much as digits as its factorization.

133409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1950.

The product of its (nonzero) digits is 324, while the sum is 20.

The square root of 133409 is about 365.2519678250. The cubic root of 133409 is about 51.0969576788.

The spelling of 133409 in words is "one hundred thirty-three thousand, four hundred nine".