991166 has 8 divisors (see below), whose sum is σ = 1621944. Its totient is φ = 450520.

The previous prime is 991147. The next prime is 991171. The reversal of 991166 is 661199.

It is a happy number.

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

991166 is a strobogrammatic number because it is the same when read upside-down.

It is a zygodrome in base 10.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 991166.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22505 + ... + 22548.

It is an arithmetic number, because the mean of its divisors is an integer number (202743).

2⁹⁹¹¹⁶⁶ is an apocalyptic number.

991166 is a deficient number, since it is larger than the sum of its proper divisors (630778).

991166 is a wasteful number, since it uses less digits than its factorization.

991166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45066.

The product of its digits is 2916, while the sum is 32.

The square root of 991166 is about 995.5732017285. The cubic root of 991166 is about 99.7046619464.

The spelling of 991166 in words is "nine hundred ninety-one thousand, one hundred sixty-six".