43399 has 2 divisors, whose sum is σ = 43400. Its totient is φ = 43398.

The previous prime is 43397. The next prime is 43403. The reversal of 43399 is 99334.

43399 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

43399 is an esthetic number in base 16, because in such base its adjacent digits differ by 1.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 43399 - 2¹ = 43397 is a prime.

Together with 43397, it forms a pair of twin primes.

It is a nialpdrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21699 + 21700.

It is an arithmetic number, because the mean of its divisors is an integer number (21700).

2⁴³³⁹⁹ is an apocalyptic number.

43399 is a deficient number, since it is larger than the sum of its proper divisors (1).

43399 is an equidigital number, since it uses as much as digits as its factorization.

43399 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2916, while the sum is 28.

The square root of 43399 is about 208.3242664694. The cubic root of 43399 is about 35.1420080749.

It can be divided in two parts, 4 and 3399, that added together give a triangular number (3403 = T₈₂).

The spelling of 43399 in words is "forty-three thousand, three hundred ninety-nine".