99998 has 4 divisors (see below), whose sum is σ = 150000. Its totient is φ = 49998.

The previous prime is 99991. The next prime is 100003. The reversal of 99998 is 89999.

It is a semiprime because it is the product of two primes.

It is a magnanimous number.

It is a nialpdrome in base 10.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 99998.

It is not an unprimeable number, because it can be changed into a prime (99991) by changing a digit.

99998 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 24998 + ... + 25001.

It is an arithmetic number, because the mean of its divisors is an integer number (37500).

2⁹⁹⁹⁹⁸ is an apocalyptic number.

99998 is a deficient number, since it is larger than the sum of its proper divisors (50002).

99998 is a wasteful number, since it uses less digits than its factorization.

99998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50001.

The product of its digits is 52488, while the sum is 44.

The square root of 99998 is about 316.2246037234. The cubic root of 99998 is about 46.4155788948.

Subtracting from 99998 its reverse (89999), we obtain a palindrome (9999).

The spelling of 99998 in words is "ninety-nine thousand, nine hundred ninety-eight".