9647991 has 20 divisors (see below), whose sum is σ = 15173400. Its totient is φ = 6092496.

The previous prime is 9647987. The next prime is 9648011. The reversal of 9647991 is 1997469.

9647991 is a `hidden beast` number, since 96 + 479 + 91 = 666.

It is not a de Polignac number, because 9647991 - 2² = 9647987 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9647291) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1596 + ... + 4673.

It is an arithmetic number, because the mean of its divisors is an integer number (758670).

Almost surely, 2^9647991 is an apocalyptic number.

9647991 is a deficient number, since it is larger than the sum of its proper divisors (5525409).

9647991 is a wasteful number, since it uses less digits than its factorization.

9647991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6300 (or 6291 counting only the distinct ones).

The product of its digits is 122472, while the sum is 45.

The square root of 9647991 is about 3106.1215365790. The cubic root of 9647991 is about 212.8852784325.

The spelling of 9647991 in words is "nine million, six hundred forty-seven thousand, nine hundred ninety-one".