8643889 has 2 divisors, whose sum is σ = 8643890. Its totient is φ = 8643888.

The previous prime is 8643851. The next prime is 8643893. The reversal of 8643889 is 9883468.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8643600 + 289 = 2940^2 + 17^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8643889 is a prime.

8643889 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (8643839) 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, 4321944 + 4321945.

It is an arithmetic number, because the mean of its divisors is an integer number (4321945).

Almost surely, 2^8643889 is an apocalyptic number.

It is an amenable number.

8643889 is a deficient number, since it is larger than the sum of its proper divisors (1).

8643889 is an equidigital number, since it uses as much as digits as its factorization.

8643889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 331776, while the sum is 46.

The square root of 8643889 is about 2940.0491492490. The cubic root of 8643889 is about 205.2278964666.

It can be divided in two parts, 864 and 3889, that added together give a triangular number (4753 = T₉₇).

The spelling of 8643889 in words is "eight million, six hundred forty-three thousand, eight hundred eighty-nine".