999797999 has 8 divisors (see below), whose sum is σ = 1073112480. Its totient is φ = 928094976.

The previous prime is 999797987. The next prime is 999798001.

It is a happy number.

999797999 is nontrivially palindromic in base 10.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-999797999 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999797699) 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, 401579 + ... + 404060.

It is an arithmetic number, because the mean of its divisors is an integer number (134139060).

Almost surely, 2^999797999 is an apocalyptic number.

999797999 is a deficient number, since it is larger than the sum of its proper divisors (73314481).

999797999 is a wasteful number, since it uses less digits than its factorization.

999797999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 805729.

The product of its digits is 234365481, while the sum is 77.

The square root of 999797999 is about 31619.5825241258. The cubic root of 999797999 is about 999.9326617990.

The spelling of 999797999 in words is "nine hundred ninety-nine million, seven hundred ninety-seven thousand, nine hundred ninety-nine".