991101 has 8 divisors (see below), whose sum is σ = 1364224. Its totient is φ = 639360.

The previous prime is 991091. The next prime is 991127. The reversal of 991101 is 101199.

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

It is not a de Polignac number, because 991101 - 2⁵ = 991069 is a prime.

It is a Duffinian 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 (991171) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5236 + ... + 5421.

It is an arithmetic number, because the mean of its divisors is an integer number (170528).

2⁹⁹¹¹⁰¹ is an apocalyptic number.

It is an amenable number.

991101 is a deficient number, since it is larger than the sum of its proper divisors (373123).

991101 is a wasteful number, since it uses less digits than its factorization.

991101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10691.

The product of its (nonzero) digits is 81, while the sum is 21.

The square root of 991101 is about 995.5405566826. The cubic root of 991101 is about 99.7024823772.

The spelling of 991101 in words is "nine hundred ninety-one thousand, one hundred one".