133523 has 4 divisors (see below), whose sum is σ = 143808. Its totient is φ = 123240.

The previous prime is 133519. The next prime is 133541. The reversal of 133523 is 325331.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 325331 = 263 ⋅1237.

It is not a de Polignac number, because 133523 - 2² = 133519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (133543) 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, 5123 + ... + 5148.

It is an arithmetic number, because the mean of its divisors is an integer number (35952).

2¹³³⁵²³ is an apocalyptic number.

133523 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

133523 is a deficient number, since it is larger than the sum of its proper divisors (10285).

133523 is a wasteful number, since it uses less digits than its factorization.

133523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10284.

The product of its digits is 270, while the sum is 17.

The square root of 133523 is about 365.4079911551. The cubic root of 133523 is about 51.1115079084. Note that the first 3 decimals are identical.

Adding to 133523 its reverse (325331), we get a palindrome (458854).

It can be divided in two parts, 133 and 523, that added together give a palindrome (656).

The spelling of 133523 in words is "one hundred thirty-three thousand, five hundred twenty-three".