133555 has 4 divisors (see below), whose sum is σ = 160272. Its totient is φ = 106840.

The previous prime is 133543. The next prime is 133559. The reversal of 133555 is 555331.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 555331 = 7 ⋅79333.

It is not a de Polignac number, because 133555 - 2¹¹ = 131507 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a plaindrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (133559) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13351 + ... + 13360.

It is an arithmetic number, because the mean of its divisors is an integer number (40068).

2¹³³⁵⁵⁵ is an apocalyptic number.

133555 is a deficient number, since it is larger than the sum of its proper divisors (26717).

133555 is an equidigital number, since it uses as much as digits as its factorization.

133555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26716.

The product of its digits is 1125, while the sum is 22.

The square root of 133555 is about 365.4517752043. The cubic root of 133555 is about 51.1155906947.

Adding to 133555 its reverse (555331), we get a palindrome (688886).

The spelling of 133555 in words is "one hundred thirty-three thousand, five hundred fifty-five".