999939799 has 2 divisors, whose sum is σ = 999939800. Its totient is φ = 999939798.

The previous prime is 999939797. The next prime is 999939821. The reversal of 999939799 is 997939999.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 999939799 - 2¹ = 999939797 is a prime.

Together with 999939797, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999939797) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499969899 + 499969900.

It is an arithmetic number, because the mean of its divisors is an integer number (499969900).

Almost surely, 2^999939799 is an apocalyptic number.

999939799 is a deficient number, since it is larger than the sum of its proper divisors (1).

999939799 is an equidigital number, since it uses as much as digits as its factorization.

999939799 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 100442349, while the sum is 73.

The square root of 999939799 is about 31621.8247259705. The cubic root of 999939799 is about 999.9799325973.

The spelling of 999939799 in words is "nine hundred ninety-nine million, nine hundred thirty-nine thousand, seven hundred ninety-nine".