899999999 has 16 divisors (see below), whose sum is σ = 959376000. Its totient is φ = 841894560.

The previous prime is 899999963. The next prime is 900000011. The reversal of 899999999 is 999999998.

It is a Cunningham number, because it is equal to 30000²-1.

It is not a de Polignac number, because 899999999 - 2⁸ = 899999743 is a prime.

It is a Duffinian number.

899999999 is a modest number, since divided by 99999 gives 8999 as remainder.

It is a plaindrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (899999929) 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 15 ways as a sum of consecutive naturals, for example, 569192 + ... + 570770.

It is an arithmetic number, because the mean of its divisors is an integer number (59961000).

Almost surely, 2^899999999 is an apocalyptic number.

899999999 is a deficient number, since it is larger than the sum of its proper divisors (59376001).

899999999 is a wasteful number, since it uses less digits than its factorization.

899999999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1958.

The product of its digits is 344373768, while the sum is 80.

The square root of 899999999 is about 29999.9999833333. Note that the first 4 decimals coincide. The cubic root of 899999999 is about 965.4893842480.

Subtracting 899999999 from its reverse (999999998), we obtain a palindrome (99999999).

The spelling of 899999999 in words is "eight hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred ninety-nine".