133491 has 4 divisors (see below), whose sum is σ = 177992. Its totient is φ = 88992.

The previous prime is 133481. The next prime is 133493. The reversal of 133491 is 194331.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 133491 - 2¹³ = 125299 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (133493) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22246 + ... + 22251.

It is an arithmetic number, because the mean of its divisors is an integer number (44498).

2¹³³⁴⁹¹ is an apocalyptic number.

133491 is a deficient number, since it is larger than the sum of its proper divisors (44501).

133491 is an equidigital number, since it uses as much as digits as its factorization.

133491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44500.

The product of its digits is 324, while the sum is 21.

The square root of 133491 is about 365.3642018589. The cubic root of 133491 is about 51.1074244698.

The spelling of 133491 in words is "one hundred thirty-three thousand, four hundred ninety-one".