9991001033 has 8 divisors (see below), whose sum is σ = 11130558600. Its totient is φ = 8904446208.

The previous prime is 9991000967. The next prime is 9991001051. The reversal of 9991001033 is 3301001999.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 588208009 + 9402793024 = 24253^2 + 96968^2 .

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 9991001033 - 2¹⁴ = 9990984649 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 9991000984 and 9991001002.

It is not an unprimeable number, because it can be changed into a prime (9991001063) 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, 13250288 + ... + 13251041.

It is an arithmetic number, because the mean of its divisors is an integer number (1391319825).

Almost surely, 2^9991001033 is an apocalyptic number.

It is an amenable number.

9991001033 is a deficient number, since it is larger than the sum of its proper divisors (1139557567).

9991001033 is a wasteful number, since it uses less digits than its factorization.

9991001033 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26501371.

The product of its (nonzero) digits is 6561, while the sum is 35.

The square root of 9991001033 is about 99954.9950377669. The cubic root of 9991001033 is about 2153.7882398577.

The spelling of 9991001033 in words is "nine billion, nine hundred ninety-one million, one thousand, thirty-three".