9984991 has 2 divisors, whose sum is σ = 9984992. Its totient is φ = 9984990.

The previous prime is 9984979. The next prime is 9985021. The reversal of 9984991 is 1994899.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 9984991 - 2⁹ = 9984479 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9984941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4992495 + 4992496.

It is an arithmetic number, because the mean of its divisors is an integer number (4992496).

Almost surely, 2^9984991 is an apocalyptic number.

9984991 is a deficient number, since it is larger than the sum of its proper divisors (1).

9984991 is an equidigital number, since it uses as much as digits as its factorization.

9984991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 209952, while the sum is 49.

The square root of 9984991 is about 3159.9036377713. The cubic root of 9984991 is about 215.3356286651.

The spelling of 9984991 in words is "nine million, nine hundred eighty-four thousand, nine hundred ninety-one".