999998845 has 4 divisors (see below), whose sum is σ = 1199998620. Its totient is φ = 799999072.

The previous prime is 999998843. The next prime is 999998863. The reversal of 999998845 is 548899999.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 548899999 = 83 ⋅6613253.

It can be written as a sum of positive squares in 2 ways, for example, as 353364804 + 646634041 = 18798^2 + 25429^2 .

It is a cyclic number.

It is not a de Polignac number, because 999998845 - 2¹ = 999998843 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999998843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 99999880 + ... + 99999889.

It is an arithmetic number, because the mean of its divisors is an integer number (299999655).

Almost surely, 2^999998845 is an apocalyptic number.

It is an amenable number.

999998845 is a deficient number, since it is larger than the sum of its proper divisors (199999775).

999998845 is a wasteful number, since it uses less digits than its factorization.

999998845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199999774.

The product of its digits is 75582720, while the sum is 70.

The square root of 999998845 is about 31622.7583395250. The cubic root of 999998845 is about 999.9996149999. Note that the first 3 decimals are identical.

The spelling of 999998845 in words is "nine hundred ninety-nine million, nine hundred ninety-eight thousand, eight hundred forty-five".