84391 has 2 divisors, whose sum is σ = 84392.
Its totient is φ = 84390.
The previous prime is 84389. The next prime is 84401. The reversal of 84391 is 19348.
It is a weak prime.
It is a cyclic number.
It is not a de Polignac number, because 84391 - 21 = 84389 is a prime.
Together with 84389, it forms a pair of twin primes.
It is the 291-st Hogben number.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (84191) by changing a digit.
It is a nontrivial repunit in base 290.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42195 + 42196.
It is an arithmetic number, because the mean of its divisors is an integer number (42196).
284391 is an apocalyptic number.
84391 is a deficient number, since it is larger than the sum of its proper divisors (1).
84391 is an equidigital number, since it uses as much as digits as its factorization.
84391 is an odious number, because the sum of its binary digits is odd.
The product of its digits is 864, while the sum is 25.
The square root of 84391 is about 290.5012908749.
The cubic root of 84391 is about 43.8630383000.
The spelling of 84391 in words is "eighty-four thousand, three hundred ninety-one".