991101001 has 8 divisors (see below), whose sum is σ = 1081977984. Its totient is φ = 900353520.

The previous prime is 991100987. The next prime is 991101017. The reversal of 991101001 is 100101199.

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

It is a de Polignac number, because none of the positive numbers 2^k-991101001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (991101401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16006 + ... + 47311.

It is an arithmetic number, because the mean of its divisors is an integer number (135247248).

Almost surely, 2^991101001 is an apocalyptic number.

It is an amenable number.

991101001 is a deficient number, since it is larger than the sum of its proper divisors (90876983).

991101001 is a wasteful number, since it uses less digits than its factorization.

991101001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64751.

The product of its (nonzero) digits is 81, while the sum is 22.

The square root of 991101001 is about 31481.7566377736. The cubic root of 991101001 is about 997.0248241068.

The spelling of 991101001 in words is "nine hundred ninety-one million, one hundred one thousand, one".