9919781166 has 8 divisors (see below), whose sum is σ = 19839562344. Its totient is φ = 3306593720.

The previous prime is 9919781161. The next prime is 9919781167. The reversal of 9919781166 is 6611879199.

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

9919781166 is an admirable number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9919781161) 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, 826648425 + ... + 826648436.

It is an arithmetic number, because the mean of its divisors is an integer number (2479945293).

Almost surely, 2^9919781166 is an apocalyptic number.

9919781166 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.

9919781166 is a wasteful number, since it uses less digits than its factorization.

9919781166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1653296866.

The product of its digits is 1469664, while the sum is 57.

The square root of 9919781166 is about 99598.0982047348. The cubic root of 9919781166 is about 2148.6583420312.

The spelling of 9919781166 in words is "nine billion, nine hundred nineteen million, seven hundred eighty-one thousand, one hundred sixty-six".