991991046066 has 8 divisors (see below), whose sum is σ = 1983982092144. Its totient is φ = 330663682020.

The previous prime is 991991046061. The next prime is 991991046119. The reversal of 991991046066 is 660640199199.

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

991991046066 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (991991046061) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 82665920500 + ... + 82665920511.

It is an arithmetic number, because the mean of its divisors is an integer number (247997761518).

Almost surely, 2^991991046066 is an apocalyptic number.

991991046066 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

991991046066 is a wasteful number, since it uses less digits than its factorization.

991991046066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165331841016.

The product of its (nonzero) digits is 5668704, while the sum is 60.

The spelling of 991991046066 in words is "nine hundred ninety-one billion, nine hundred ninety-one million, forty-six thousand, sixty-six".