133605 has 12 divisors (see below), whose sum is σ = 231660. Its totient is φ = 71232.

The previous prime is 133597. The next prime is 133631. The reversal of 133605 is 506331.

It can be written as a sum of positive squares in 2 ways, for example, as 16641 + 116964 = 129^2 + 342^2 .

It is not a de Polignac number, because 133605 - 2³ = 133597 is a prime.

133605 is a lucky number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1440 + ... + 1529.

It is an arithmetic number, because the mean of its divisors is an integer number (19305).

2¹³³⁶⁰⁵ is an apocalyptic number.

133605 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

133605 is a deficient number, since it is larger than the sum of its proper divisors (98055).

133605 is a wasteful number, since it uses less digits than its factorization.

133605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2980 (or 2977 counting only the distinct ones).

The product of its (nonzero) digits is 270, while the sum is 18.

The square root of 133605 is about 365.5201772816. The cubic root of 133605 is about 51.1219687428.

Adding to 133605 its reverse (506331), we get a palindrome (639936).

The spelling of 133605 in words is "one hundred thirty-three thousand, six hundred five".