9991599226812 has 72 divisors (see below), whose sum is σ = 29162193461856. Its totient is φ = 2825312292864.

The previous prime is 9991599226799. The next prime is 9991599226841. The reversal of 9991599226812 is 2186229951999.

9991599226812 is a `hidden beast` number, since 9 + 9 + 9 + 1 + 599 + 2 + 26 + 8 + 1 + 2 = 666.

It is a hoax number, since the sum of its digits (72) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 204352893 + ... + 204401780.

It is an arithmetic number, because the mean of its divisors is an integer number (405030464748).

Almost surely, 2^{9991599226812} is an apocalyptic number.

It is an amenable number.

9991599226812 is an abundant number, since it is smaller than the sum of its proper divisors (19170594235044).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

9991599226812 is a wasteful number, since it uses less digits than its factorization.

9991599226812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 408754787 (or 408754782 counting only the distinct ones).

The product of its digits is 113374080, while the sum is 72.

The spelling of 9991599226812 in words is "nine trillion, nine hundred ninety-one billion, five hundred ninety-nine million, two hundred twenty-six thousand, eight hundred twelve".