133805 has 8 divisors (see below), whose sum is σ = 183552. Its totient is φ = 91728.

The previous prime is 133801. The next prime is 133811. The reversal of 133805 is 508331.

133805 = T₁₂₆ + T₁₂₇ + ... + T₁₄₀.

133805 = 44² + 45² + ... + 78².

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 133805 - 2² = 133801 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133801) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1877 + ... + 1946.

It is an arithmetic number, because the mean of its divisors is an integer number (22944).

2¹³³⁸⁰⁵ is an apocalyptic number.

It is an amenable number.

133805 is a deficient number, since it is larger than the sum of its proper divisors (49747).

133805 is an equidigital number, since it uses as much as digits as its factorization.

133805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3835.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 133805 is about 365.7936576815. The cubic root of 133805 is about 51.1474650346.

The spelling of 133805 in words is "one hundred thirty-three thousand, eight hundred five".