9216991 has 8 divisors (see below), whose sum is σ = 10605600. Its totient is φ = 7846368.

The previous prime is 9216979. The next prime is 9217001. The reversal of 9216991 is 1996129.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 9216991 - 2¹⁷ = 9085919 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 9216991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9216191) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3376 + ... + 5461.

It is an arithmetic number, because the mean of its divisors is an integer number (1325700).

Almost surely, 2^9216991 is an apocalyptic number.

9216991 is a deficient number, since it is larger than the sum of its proper divisors (1388609).

9216991 is a wasteful number, since it uses less digits than its factorization.

9216991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8993.

The product of its digits is 8748, while the sum is 37.

The square root of 9216991 is about 3035.9497690179. The cubic root of 9216991 is about 209.6668261826. Note that the first 3 decimals are identical.

The spelling of 9216991 in words is "nine million, two hundred sixteen thousand, nine hundred ninety-one".