999998885 has 4 divisors (see below), whose sum is σ = 1199998668. Its totient is φ = 799999104.

The previous prime is 999998869. The next prime is 999998903. The reversal of 999998885 is 588899999.

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: 588899999 = 491 ⋅1199389.

It can be written as a sum of positive squares in 2 ways, for example, as 496131076 + 503867809 = 22274^2 + 22447^2 .

It is a cyclic number.

It is not a de Polignac number, because 999998885 - 2⁴ = 999998869 is a prime.

It is a Duffinian 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 (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 99999884 + ... + 99999893.

It is an arithmetic number, because the mean of its divisors is an integer number (299999667).

Almost surely, 2^999998885 is an apocalyptic number.

It is an amenable number.

999998885 is a deficient number, since it is larger than the sum of its proper divisors (199999783).

999998885 is a wasteful number, since it uses less digits than its factorization.

999998885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199999782.

The product of its digits is 151165440, while the sum is 74.

The square root of 999998885 is about 31622.7589719809. The cubic root of 999998885 is about 999.9996283332. Note that the first 3 decimals are identical.

The spelling of 999998885 in words is "nine hundred ninety-nine million, nine hundred ninety-eight thousand, eight hundred eighty-five".