991033 has 4 divisors (see below), whose sum is σ = 993168. Its totient is φ = 988900.

The previous prime is 991031. The next prime is 991037. The reversal of 991033 is 330199.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 991033 - 2¹ = 991031 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 990989 and 991007.

It is not an unprimeable number, because it can be changed into a prime (991031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43 + ... + 1408.

It is an arithmetic number, because the mean of its divisors is an integer number (248292).

2⁹⁹¹⁰³³ is an apocalyptic number.

It is an amenable number.

991033 is a deficient number, since it is larger than the sum of its proper divisors (2135).

991033 is a wasteful number, since it uses less digits than its factorization.

991033 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2134.

The product of its (nonzero) digits is 729, while the sum is 25.

The square root of 991033 is about 995.5064037966. The cubic root of 991033 is about 99.7002021104.

The spelling of 991033 in words is "nine hundred ninety-one thousand, thirty-three".