991199933 has 4 divisors (see below), whose sum is σ = 991270560. Its totient is φ = 991129308.

The previous prime is 991199917. The next prime is 991199947. The reversal of 991199933 is 339991199.

991199933 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 991199933 - 2⁴ = 991199917 is a prime.

It is a Duffinian number.

It is a zygodrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991199533) 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, 6335 + ... + 44972.

It is an arithmetic number, because the mean of its divisors is an integer number (247817640).

Almost surely, 2^991199933 is an apocalyptic number.

It is an amenable number.

991199933 is a deficient number, since it is larger than the sum of its proper divisors (70627).

991199933 is a wasteful number, since it uses less digits than its factorization.

991199933 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70626.

The product of its digits is 531441, while the sum is 53.

The square root of 991199933 is about 31483.3278577726. The cubic root of 991199933 is about 997.0579974423.

The spelling of 991199933 in words is "nine hundred ninety-one million, one hundred ninety-nine thousand, nine hundred thirty-three".