9899999 has 2 divisors, whose sum is σ = 9900000. Its totient is φ = 9899998.

The previous prime is 9899993. The next prime is 9900047. The reversal of 9899999 is 9999989.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9899999 is a prime.

9899999 is a modest number, since divided by 9999 gives 989 as remainder.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9899993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4949999 + 4950000.

It is an arithmetic number, because the mean of its divisors is an integer number (4950000).

Almost surely, 2^9899999 is an apocalyptic number.

9899999 is a deficient number, since it is larger than the sum of its proper divisors (1).

9899999 is an equidigital number, since it uses as much as digits as its factorization.

9899999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4251528, while the sum is 62.

The square root of 9899999 is about 3146.4263856000. The cubic root of 9899999 is about 214.7229096722.

The spelling of 9899999 in words is "nine million, eight hundred ninety-nine thousand, nine hundred ninety-nine".