1991845326186 has 16 divisors (see below), whose sum is σ = 4426322947200. Its totient is φ = 663948442044.

The previous prime is 1991845326181. The next prime is 1991845326269. The reversal of 1991845326186 is 6816235481991.

1991845326186 is a `hidden beast` number, since 1 + 9 + 9 + 1 + 8 + 4 + 5 + 3 + 2 + 618 + 6 = 666.

It is not an unprimeable number, because it can be changed into a prime (1991845326181) 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, 18443012226 + ... + 18443012333.

It is an arithmetic number, because the mean of its divisors is an integer number (276645184200).

Almost surely, 2^{1991845326186} is an apocalyptic number.

1991845326186 is an abundant number, since it is smaller than the sum of its proper divisors (2434477621014).

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

1991845326186 is a wasteful number, since it uses less digits than its factorization.

1991845326186 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36886024570 (or 36886024564 counting only the distinct ones).

The product of its digits is 22394880, while the sum is 63.

The spelling of 1991845326186 in words is "one trillion, nine hundred ninety-one billion, eight hundred forty-five million, three hundred twenty-six thousand, one hundred eighty-six".