136491 has 4 divisors (see below), whose sum is σ = 181992. Its totient is φ = 90992.

The previous prime is 136483. The next prime is 136501. The reversal of 136491 is 194631.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 194631 = 3 ⋅64877.

It is a cyclic number.

It is not a de Polignac number, because 136491 - 2³ = 136483 is a prime.

It is a D-number.

136491 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (136421) 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, 22746 + ... + 22751.

It is an arithmetic number, because the mean of its divisors is an integer number (45498).

2¹³⁶⁴⁹¹ is an apocalyptic number.

136491 is a deficient number, since it is larger than the sum of its proper divisors (45501).

136491 is an equidigital number, since it uses as much as digits as its factorization.

136491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45500.

The product of its digits is 648, while the sum is 24.

The square root of 136491 is about 369.4468838683. The cubic root of 136491 is about 51.4874447038.

The spelling of 136491 in words is "one hundred thirty-six thousand, four hundred ninety-one".