1999800005 has 18 divisors (see below), whose sum is σ = 2792534994. Its totient is φ = 1370811456.

The previous prime is 1999799959. The next prime is 1999800031. The reversal of 1999800005 is 5000089991.

It can be written as a sum of positive squares in 3 ways, for example, as 458216836 + 1541583169 = 21406^2 + 39263^2 .

It is not a de Polignac number, because 1999800005 - 2⁶ = 1999799941 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 698537 + ... + 701393.

It is an arithmetic number, because the mean of its divisors is an integer number (155140833).

Almost surely, 2^1999800005 is an apocalyptic number.

It is an amenable number.

1999800005 is a deficient number, since it is larger than the sum of its proper divisors (792734989).

1999800005 is an frugal number, since it uses more digits than its factorization.

1999800005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5733 (or 2869 counting only the distinct ones).

The product of its (nonzero) digits is 29160, while the sum is 41.

The square root of 1999800005 is about 44719.1234820183. The cubic root of 1999800005 is about 1259.8790521766.

Adding to 1999800005 its reverse (5000089991), we get a palindrome (6999889996).

The spelling of 1999800005 in words is "one billion, nine hundred ninety-nine million, eight hundred thousand, five".