8642991 has 16 divisors (see below), whose sum is σ = 13309184. Its totient is φ = 4886784.

The previous prime is 8642989. The next prime is 8643013. The reversal of 8642991 is 1992468.

It is not a de Polignac number, because 8642991 - 2¹ = 8642989 is a prime.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8642911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 85 + ... + 4158.

It is an arithmetic number, because the mean of its divisors is an integer number (831824).

Almost surely, 2^8642991 is an apocalyptic number.

8642991 is a deficient number, since it is larger than the sum of its proper divisors (4666193).

8642991 is a wasteful number, since it uses less digits than its factorization.

8642991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4350.

The product of its digits is 31104, while the sum is 39.

The square root of 8642991 is about 2939.8964267470. The cubic root of 8642991 is about 205.2207892863.

The spelling of 8642991 in words is "eight million, six hundred forty-two thousand, nine hundred ninety-one".