135381 has 4 divisors (see below), whose sum is σ = 180512. Its totient is φ = 90252.

The previous prime is 135367. The next prime is 135389. The reversal of 135381 is 183531.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 135381 - 2⁵ = 135349 is a prime.

It is a super-2 number, since 2×135381² = 36656030322, which contains 22 as substring.

It is a D-number.

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 (135389) 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, 22561 + ... + 22566.

It is an arithmetic number, because the mean of its divisors is an integer number (45128).

2¹³⁵³⁸¹ is an apocalyptic number.

It is an amenable number.

135381 is a deficient number, since it is larger than the sum of its proper divisors (45131).

135381 is an equidigital number, since it uses as much as digits as its factorization.

135381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45130.

The product of its digits is 360, while the sum is 21.

The square root of 135381 is about 367.9415714485. The cubic root of 135381 is about 51.3474923930.

The spelling of 135381 in words is "one hundred thirty-five thousand, three hundred eighty-one".