991100105 has 8 divisors (see below), whose sum is σ = 1195358472. Its totient is φ = 788854528.

The previous prime is 991100083. The next prime is 991100111. The reversal of 991100105 is 501001199.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 480837184 + 510262921 = 21928^2 + 22589^2 .

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 991100105 - 2⁸ = 991099849 is a prime.

It is a super-2 number, since 2×991100105² = 1964558836262022050, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

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, 502112 + ... + 504081.

It is an arithmetic number, because the mean of its divisors is an integer number (149419809).

Almost surely, 2^991100105 is an apocalyptic number.

It is an amenable number.

991100105 is a deficient number, since it is larger than the sum of its proper divisors (204258367).

991100105 is a wasteful number, since it uses less digits than its factorization.

991100105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1006395.

The product of its (nonzero) digits is 405, while the sum is 26.

The square root of 991100105 is about 31481.7424073065. The cubic root of 991100105 is about 997.0245236549.

The spelling of 991100105 in words is "nine hundred ninety-one million, one hundred thousand, one hundred five".