991333 has 4 divisors (see below), whose sum is σ = 1132960. Its totient is φ = 849708.

The previous prime is 991327. The next prime is 991343. The reversal of 991333 is 333199.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 333199 = 101 ⋅3299.

It is a cyclic number.

It is not a de Polignac number, because 991333 - 2¹³ = 983141 is a prime.

It is a super-2 number, since 2×991333² = 1965482233778, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991313) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 70803 + ... + 70816.

It is an arithmetic number, because the mean of its divisors is an integer number (283240).

2⁹⁹¹³³³ is an apocalyptic number.

It is an amenable number.

991333 is a deficient number, since it is larger than the sum of its proper divisors (141627).

991333 is a wasteful number, since it uses less digits than its factorization.

991333 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141626.

The product of its digits is 2187, while the sum is 28.

The square root of 991333 is about 995.6570694772. The cubic root of 991333 is about 99.7102613258.

The spelling of 991333 in words is "nine hundred ninety-one thousand, three hundred thirty-three".