133381 has 4 divisors (see below), whose sum is σ = 135072. Its totient is φ = 131692.

The previous prime is 133379. The next prime is 133387. The reversal of 133381 is 183331.

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, and also an emirpimes, since its reverse is a distinct semiprime: 183331 = 19 ⋅9649.

It is a cyclic number.

It is not a de Polignac number, because 133381 - 2¹ = 133379 is a prime.

It is a super-2 number, since 2×133381² = 35580982322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 721 + ... + 886.

It is an arithmetic number, because the mean of its divisors is an integer number (33768).

2¹³³³⁸¹ is an apocalyptic number.

It is an amenable number.

133381 is a deficient number, since it is larger than the sum of its proper divisors (1691).

133381 is an equidigital number, since it uses as much as digits as its factorization.

133381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1690.

The product of its digits is 216, while the sum is 19.

The square root of 133381 is about 365.2136361091. The cubic root of 133381 is about 51.0933826703.

The spelling of 133381 in words is "one hundred thirty-three thousand, three hundred eighty-one".