999990099998 has 4 divisors (see below), whose sum is σ = 1499985150000. Its totient is φ = 499995049998.

The previous prime is 999990099973. The next prime is 999990100001. The reversal of 999990099998 is 899990099999.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 899990099999 = 53 ⋅16980945283.

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, 249997524998 + ... + 249997525001.

It is an arithmetic number, because the mean of its divisors is an integer number (374996287500).

Almost surely, 2^999990099998 is an apocalyptic number.

999990099998 is a deficient number, since it is larger than the sum of its proper divisors (499995050002).

999990099998 is a wasteful number, since it uses less digits than its factorization.

999990099998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 499995050001.

The product of its (nonzero) digits is 3099363912, while the sum is 89.

Subtracting from 999990099998 its reverse (899990099999), we obtain a palindrome (99999999999).

The spelling of 999990099998 in words is "nine hundred ninety-nine billion, nine hundred ninety million, ninety-nine thousand, nine hundred ninety-eight".