990984191 has 2 divisors, whose sum is σ = 990984192. Its totient is φ = 990984190.

The previous prime is 990984173. The next prime is 990984217. The reversal of 990984191 is 191489099.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-990984191 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (990984131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495492095 + 495492096.

It is an arithmetic number, because the mean of its divisors is an integer number (495492096).

Almost surely, 2^990984191 is an apocalyptic number.

990984191 is a deficient number, since it is larger than the sum of its proper divisors (1).

990984191 is an equidigital number, since it uses as much as digits as its factorization.

990984191 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 209952, while the sum is 50.

The square root of 990984191 is about 31479.9013816753. The cubic root of 990984191 is about 996.9856531763.

The spelling of 990984191 in words is "nine hundred ninety million, nine hundred eighty-four thousand, one hundred ninety-one".