9991324786 has 16 divisors (see below), whose sum is σ = 15381240984. Its totient is φ = 4865620864.

The previous prime is 9991324771. The next prime is 9991324787. The reversal of 9991324786 is 6874231999.

It can be written as a sum of positive squares in 4 ways, for example, as 9728074161 + 263250625 = 98631^2 + 16225^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 9991324786.

It is not an unprimeable number, because it can be changed into a prime (9991324787) 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, 329485 + ... + 358528.

Almost surely, 2^9991324786 is an apocalyptic number.

9991324786 is a deficient number, since it is larger than the sum of its proper divisors (5389916198).

9991324786 is a wasteful number, since it uses less digits than its factorization.

9991324786 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 688205.

The product of its digits is 5878656, while the sum is 58.

The square root of 9991324786 is about 99956.6145185000. The cubic root of 9991324786 is about 2153.8115037218.

The spelling of 9991324786 in words is "nine billion, nine hundred ninety-one million, three hundred twenty-four thousand, seven hundred eighty-six".