999998 has 12 divisors (see below), whose sum is σ = 1560672. Its totient is φ = 480060.

The previous prime is 999983. The next prime is 1000003. The reversal of 999998 is 899999.

It is a happy number.

It is a nialpdrome in base 10.

It is a congruent number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 7811 + ... + 7937.

It is an arithmetic number, because the mean of its divisors is an integer number (130056).

2⁹⁹⁹⁹⁹⁸ is an apocalyptic number.

999998 is a deficient number, since it is larger than the sum of its proper divisors (560674).

999998 is a wasteful number, since it uses less digits than its factorization.

999998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 287 (or 160 counting only the distinct ones).

The product of its digits is 472392, while the sum is 53.

The square root of 999998 is about 999.9989999995. The cubic root of 999998 is about 99.9999333333. Note that the first 4 decimals are identical.

Subtracting from 999998 its reverse (899999), we obtain a palindrome (99999).

The spelling of 999998 in words is "nine hundred ninety-nine thousand, nine hundred ninety-eight".