9991667 has 8 divisors (see below), whose sum is σ = 11462496. Its totient is φ = 8531712.

The previous prime is 9991649. The next prime is 9991669. The reversal of 9991667 is 7661999.

It is a happy number.

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

It is not a de Polignac number, because 9991667 - 2⁶ = 9991603 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9991669) 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, 638 + ... + 4515.

It is an arithmetic number, because the mean of its divisors is an integer number (1432812).

Almost surely, 2^9991667 is an apocalyptic number.

9991667 is a deficient number, since it is larger than the sum of its proper divisors (1470829).

9991667 is a wasteful number, since it uses less digits than its factorization.

9991667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5437.

The product of its digits is 183708, while the sum is 47.

The square root of 9991667 is about 3160.9598225855. The cubic root of 9991667 is about 215.3836093589.

The spelling of 9991667 in words is "nine million, nine hundred ninety-one thousand, six hundred sixty-seven".