291439 has 2 divisors, whose sum is σ = 291440. Its totient is φ = 291438.

The previous prime is 291437. The next prime is 291443. The reversal of 291439 is 934192.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 291439 - 2¹ = 291437 is a prime.

Together with 291437, it forms a pair of twin primes.

291439 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (291437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 145719 + 145720.

It is an arithmetic number, because the mean of its divisors is an integer number (145720).

2²⁹¹⁴³⁹ is an apocalyptic number.

291439 is a deficient number, since it is larger than the sum of its proper divisors (1).

291439 is an equidigital number, since it uses as much as digits as its factorization.

291439 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1944, while the sum is 28.

The square root of 291439 is about 539.8509053433. The cubic root of 291439 is about 66.3003604269.

The spelling of 291439 in words is "two hundred ninety-one thousand, four hundred thirty-nine".