991806163 has 8 divisors (see below), whose sum is σ = 1060547040. Its totient is φ = 924220800.

The previous prime is 991806149. The next prime is 991806191. The reversal of 991806163 is 361608199.

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

It is a cyclic number.

It is not a de Polignac number, because 991806163 - 2⁹ = 991805651 is a prime.

It is not an unprimeable number, because it can be changed into a prime (991806143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 287103 + ... + 290536.

It is an arithmetic number, because the mean of its divisors is an integer number (132568380).

Almost surely, 2^991806163 is an apocalyptic number.

991806163 is a deficient number, since it is larger than the sum of its proper divisors (68740877).

991806163 is a wasteful number, since it uses less digits than its factorization.

991806163 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 577757.

The product of its (nonzero) digits is 69984, while the sum is 43.

The square root of 991806163 is about 31492.9541802607. The cubic root of 991806163 is about 997.2612269700.

The spelling of 991806163 in words is "nine hundred ninety-one million, eight hundred six thousand, one hundred sixty-three".