8391289 has 2 divisors, whose sum is σ = 8391290. Its totient is φ = 8391288.

The previous prime is 8391287. The next prime is 8391323. The reversal of 8391289 is 9821938.

8391289 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4549689 + 3841600 = 2133^2 + 1960^2 .

It is a cyclic number.

It is not a de Polignac number, because 8391289 - 2¹ = 8391287 is a prime.

Together with 8391287, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (8391283) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4195644 + 4195645.

It is an arithmetic number, because the mean of its divisors is an integer number (4195645).

Almost surely, 2^8391289 is an apocalyptic number.

It is an amenable number.

8391289 is a deficient number, since it is larger than the sum of its proper divisors (1).

8391289 is an equidigital number, since it uses as much as digits as its factorization.

8391289 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 40.

The square root of 8391289 is about 2896.7721691566. The cubic root of 8391289 is about 203.2089785775.

The spelling of 8391289 in words is "eight million, three hundred ninety-one thousand, two hundred eighty-nine".