999979799 has 16 divisors (see below), whose sum is σ = 1255867200. Its totient is φ = 791189280.

The previous prime is 999979753. The next prime is 999979811. The reversal of 999979799 is 997979999.

It is a happy number.

It is not a de Polignac number, because 999979799 - 2⁸ = 999979543 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999979699) 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, 107672 + ... + 116589.

It is an arithmetic number, because the mean of its divisors is an integer number (78491700).

Almost surely, 2^999979799 is an apocalyptic number.

999979799 is a deficient number, since it is larger than the sum of its proper divisors (255887401).

999979799 is a wasteful number, since it uses less digits than its factorization.

999979799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224295 (or 224281 counting only the distinct ones).

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

The square root of 999979799 is about 31622.4571942156. The cubic root of 999979799 is about 999.9932662880.

It can be divided in two parts, 9999 and 79799, that added together give a palindrome (89798).

The spelling of 999979799 in words is "nine hundred ninety-nine million, nine hundred seventy-nine thousand, seven hundred ninety-nine".