43391 has 2 divisors, whose sum is σ = 43392.
Its totient is φ = 43390.
The previous prime is 43331. The next prime is 43397. The reversal of 43391 is 19334.
It is a strong prime.
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-43391 is a prime.
It is a Sophie Germain prime.
It is a Chen prime.
It is a plaindrome in base 8 and base 13.
It is a nialpdrome in base 15.
It is a zygodrome in base 4.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (43397) 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, 21695 + 21696.
It is an arithmetic number, because the mean of its divisors is an integer number (21696).
243391 is an apocalyptic number.
43391 is a deficient number, since it is larger than the sum of its proper divisors (1).
43391 is an equidigital number, since it uses as much as digits as its factorization.
43391 is an odious number, because the sum of its binary digits is odd.
The product of its digits is 324, while the sum is 20.
The square root of 43391 is about 208.3050647488.
The cubic root of 43391 is about 35.1398486293.
It can be divided in two parts, 43 and 391, that added together give a palindrome (434).
The spelling of 43391 in words is "forty-three thousand, three hundred ninety-one".