999199999 has 8 divisors (see below), whose sum is σ = 1142963360. Its totient is φ = 855691776.

The previous prime is 999199991. The next prime is 999200003. The reversal of 999199999 is 999991999.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 999199999 - 2³ = 999199991 is a prime.

999199999 is a modest number, since divided by 99999 gives 9991 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999199991) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55314 + ... + 71119.

It is an arithmetic number, because the mean of its divisors is an integer number (142870420).

Almost surely, 2^999199999 is an apocalyptic number.

999199999 is a deficient number, since it is larger than the sum of its proper divisors (143763361).

999199999 is a wasteful number, since it uses less digits than its factorization.

999199999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127569.

The product of its digits is 43046721, while the sum is 73.

The square root of 999199999 is about 31610.1249443908. The cubic root of 999199999 is about 999.7332618571.

The spelling of 999199999 in words is "nine hundred ninety-nine million, one hundred ninety-nine thousand, nine hundred ninety-nine".