999999999999998 has 4 divisors (see below), whose sum is σ = 1500000000000000. Its totient is φ = 499999999999998.

The previous prime is 999999999999989. The next prime is 1000000000000037. The reversal of 999999999999998 is 899999999999999.

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

It is a super-9 number, since 9×999999999999998⁹ (a number of 136 digits) contains 999999999 as substring.

It is a nialpdrome in base 10.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 249999999999998 + ... + 250000000000001.

It is an arithmetic number, because the mean of its divisors is an integer number (375000000000000).

Almost surely, 2^{999999999999998} is an apocalyptic number.

999999999999998 is a deficient number, since it is larger than the sum of its proper divisors (500000000000002).

999999999999998 is a wasteful number, since it uses less digits than its factorization.

999999999999998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 500000000000001.

The product of its digits is 183014339639688, while the sum is 134.

Subtracting from 999999999999998 its reverse (899999999999999), we obtain a palindrome (99999999999999).

The spelling of 999999999999998 in words is "nine hundred ninety-nine trillion, nine hundred ninety-nine billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred ninety-eight".