999819943 has 2 divisors, whose sum is σ = 999819944. Its totient is φ = 999819942.

The previous prime is 999819923. The next prime is 999820069. The reversal of 999819943 is 349918999.

999819943 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is an emirp because it is prime and its reverse (349918999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 999819943 - 2¹³ = 999811751 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999819923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499909971 + 499909972.

It is an arithmetic number, because the mean of its divisors is an integer number (499909972).

Almost surely, 2^999819943 is an apocalyptic number.

999819943 is a deficient number, since it is larger than the sum of its proper divisors (1).

999819943 is an equidigital number, since it uses as much as digits as its factorization.

999819943 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5668704, while the sum is 61.

The square root of 999819943 is about 31619.9295223756. The cubic root of 999819943 is about 999.9399773974.

The spelling of 999819943 in words is "nine hundred ninety-nine million, eight hundred nineteen thousand, nine hundred forty-three".