991179866 has 8 divisors (see below), whose sum is σ = 1574226900. Its totient is φ = 466437568.

The previous prime is 991179823. The next prime is 991179869. The reversal of 991179866 is 668971199.

It can be written as a sum of positive squares in 2 ways, for example, as 987279241 + 3900625 = 31421^2 + 1975^2 .

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

It is not an unprimeable number, because it can be changed into a prime (991179869) 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, 14576141 + ... + 14576208.

Almost surely, 2^991179866 is an apocalyptic number.

991179866 is a deficient number, since it is larger than the sum of its proper divisors (583047034).

991179866 is a wasteful number, since it uses less digits than its factorization.

991179866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29152368.

The product of its digits is 1469664, while the sum is 56.

The square root of 991179866 is about 31483.0091636743. The cubic root of 991179866 is about 997.0512688644.

The spelling of 991179866 in words is "nine hundred ninety-one million, one hundred seventy-nine thousand, eight hundred sixty-six".