999999897 has 16 divisors (see below), whose sum is σ = 1446865728. Its totient is φ = 610683840.

The previous prime is 999999893. The next prime is 999999929. The reversal of 999999897 is 798999999.

It is a happy number.

It is not a de Polignac number, because 999999897 - 2² = 999999893 is a prime.

It is not an unprimeable number, because it can be changed into a prime (999999893) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 92758 + ... + 102975.

It is an arithmetic number, because the mean of its divisors is an integer number (90429108).

Almost surely, 2^999999897 is an apocalyptic number.

It is an amenable number.

999999897 is a deficient number, since it is larger than the sum of its proper divisors (446865831).

999999897 is a wasteful number, since it uses less digits than its factorization.

999999897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195880.

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

The square root of 999999897 is about 31622.7749731108. The cubic root of 999999897 is about 999.9999656667. Note that the first 4 decimals are identical.

The spelling of 999999897 in words is "nine hundred ninety-nine million, nine hundred ninety-nine thousand, eight hundred ninety-seven".