999979998 has 16 divisors (see below), whose sum is σ = 2002096656. Its totient is φ = 332970560.

The previous prime is 999979961. The next prime is 999980011. The reversal of 999979998 is 899979999.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 82911 + ... + 94202.

It is an arithmetic number, because the mean of its divisors is an integer number (125131041).

Almost surely, 2^999979998 is an apocalyptic number.

999979998 is an abundant number, since it is smaller than the sum of its proper divisors (1002116658).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

999979998 is a wasteful number, since it uses less digits than its factorization.

999979998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178059.

The product of its digits is 267846264, while the sum is 78.

The square root of 999979998 is about 31622.4603407135. The cubic root of 999979998 is about 999.9933326222.

Subtracting from 999979998 its reverse (899979999), we obtain a palindrome (99999999).

The spelling of 999979998 in words is "nine hundred ninety-nine million, nine hundred seventy-nine thousand, nine hundred ninety-eight".