991133305 has 4 divisors (see below), whose sum is σ = 1189359972. Its totient is φ = 792906640.

The previous prime is 991133291. The next prime is 991133357. The reversal of 991133305 is 503331199.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 374306409 + 616826896 = 19347^2 + 24836^2 .

It is a de Polignac number, because none of the positive numbers 2^k-991133305 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 99113326 + ... + 99113335.

It is an arithmetic number, because the mean of its divisors is an integer number (297339993).

Almost surely, 2^991133305 is an apocalyptic number.

It is an amenable number.

991133305 is a deficient number, since it is larger than the sum of its proper divisors (198226667).

991133305 is a wasteful number, since it uses less digits than its factorization.

991133305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198226666.

The product of its (nonzero) digits is 10935, while the sum is 34.

The square root of 991133305 is about 31482.2696926381. The cubic root of 991133305 is about 997.0356563496.

The spelling of 991133305 in words is "nine hundred ninety-one million, one hundred thirty-three thousand, three hundred five".