240391 has 4 divisors (see below), whose sum is σ = 241384. Its totient is φ = 239400.

The previous prime is 240379. The next prime is 240421. The reversal of 240391 is 193042.

240391 is nontrivially palindromic in base 13.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 240391 - 2⁷ = 240263 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (240341) 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, 136 + ... + 706.

It is an arithmetic number, because the mean of its divisors is an integer number (60346).

2²⁴⁰³⁹¹ is an apocalyptic number.

240391 is a deficient number, since it is larger than the sum of its proper divisors (993).

240391 is an equidigital number, since it uses as much as digits as its factorization.

240391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 992.

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

The square root of 240391 is about 490.2968488579. The cubic root of 240391 is about 62.1783798061.

The spelling of 240391 in words is "two hundred forty thousand, three hundred ninety-one".