8391663 has 12 divisors (see below), whose sum is σ = 13853008. Its totient is φ = 4795200.

The previous prime is 8391653. The next prime is 8391667. The reversal of 8391663 is 3661938.

It is a happy number.

It is not a de Polignac number, because 8391663 - 2⁹ = 8391151 is a prime.

It is a Duffinian number.

8391663 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8391667) 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 in 11 ways as a sum of consecutive naturals, for example, 66538 + ... + 66663.

Almost surely, 2^8391663 is an apocalyptic number.

8391663 is a deficient number, since it is larger than the sum of its proper divisors (5461345).

8391663 is a wasteful number, since it uses less digits than its factorization.

8391663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133214 (or 133211 counting only the distinct ones).

The product of its digits is 23328, while the sum is 36.

The square root of 8391663 is about 2896.8367230481. The cubic root of 8391663 is about 203.2119975427.

The spelling of 8391663 in words is "eight million, three hundred ninety-one thousand, six hundred sixty-three".