99998999 has 2 divisors, whose sum is σ = 99999000. Its totient is φ = 99998998.

The previous prime is 99998971. The next prime is 99999043. The reversal of 99998999 is 99989999.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99998999 is a prime.

It is a Sophie Germain 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 (99998909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49999499 + 49999500.

It is an arithmetic number, because the mean of its divisors is an integer number (49999500).

Almost surely, 2^99998999 is an apocalyptic number.

99998999 is a deficient number, since it is larger than the sum of its proper divisors (1).

99998999 is an equidigital number, since it uses as much as digits as its factorization.

99998999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 38263752, while the sum is 71.

The square root of 99998999 is about 9999.9499498747. The cubic root of 99998999 is about 464.1573346126.

The spelling of 99998999 in words is "ninety-nine million, nine hundred ninety-eight thousand, nine hundred ninety-nine".