8659991 has 4 divisors (see below), whose sum is σ = 9115800. Its totient is φ = 8204184.

The previous prime is 8659957. The next prime is 8659997. The reversal of 8659991 is 1999568.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 8659991 - 2⁶ = 8659927 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8659997) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 227876 + ... + 227913.

It is an arithmetic number, because the mean of its divisors is an integer number (2278950).

Almost surely, 2^8659991 is an apocalyptic number.

8659991 is a deficient number, since it is larger than the sum of its proper divisors (455809).

8659991 is a wasteful number, since it uses less digits than its factorization.

8659991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 455808.

The product of its digits is 174960, while the sum is 47.

The square root of 8659991 is about 2942.7862647498. The cubic root of 8659991 is about 205.3552515559.

The spelling of 8659991 in words is "eight million, six hundred fifty-nine thousand, nine hundred ninety-one".