9998999 has 4 divisors (see below), whose sum is σ = 10036440.
Its totient is φ = 9961560.
The previous prime is 9998977. The next prime is 9999047.
9998999 is nontrivially palindromic in base 10.
It is a semiprime because it is the product of two primes.
It is a cyclic number.
It is not a de Polignac number, because 9998999 - 28 = 9998743 is a prime.
It is a Duffinian number.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (9998929) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (11) of ones.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18317 + ... + 18854.
It is an arithmetic number, because the mean of its divisors is an integer number (2509110).
Almost surely, 29998999 is an apocalyptic number.
9998999 is a deficient number, since it is larger than the sum of its proper divisors (37441).
9998999 is a wasteful number, since it uses less digits than its factorization.
9998999 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 37440.
The product of its digits is 4251528, while the sum is 62.
The square root of 9998999 is about 3162.1193842105.
The cubic root of 9998999 is about 215.4362801329.
The spelling of 9998999 in words is "nine million, nine hundred ninety-eight thousand, nine hundred ninety-nine".