133865 has 8 divisors (see below), whose sum is σ = 164808. Its totient is φ = 104320.

The previous prime is 133853. The next prime is 133873. The reversal of 133865 is 568331.

It can be written as a sum of positive squares in 4 ways, for example, as 1369 + 132496 = 37^2 + 364^2 .

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

It is not a de Polignac number, because 133865 - 2⁶ = 133801 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a plaindrome in base 9.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 122 + ... + 531.

It is an arithmetic number, because the mean of its divisors is an integer number (20601).

2¹³³⁸⁶⁵ is an apocalyptic number.

It is an amenable number.

133865 is a deficient number, since it is larger than the sum of its proper divisors (30943).

133865 is an equidigital number, since it uses as much as digits as its factorization.

133865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 699.

The product of its digits is 2160, while the sum is 26.

The square root of 133865 is about 365.8756619400. The cubic root of 133865 is about 51.1551089675.

The spelling of 133865 in words is "one hundred thirty-three thousand, eight hundred sixty-five".