1999988813 has 2 divisors, whose sum is σ = 1999988814. Its totient is φ = 1999988812.

The previous prime is 1999988803. The next prime is 1999988831. The reversal of 1999988813 is 3188899991.

Together with next prime (1999988831) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1312395529 + 687593284 = 36227^2 + 26222^2 .

It is an emirp because it is prime and its reverse (3188899991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1999988813 - 2⁴ = 1999988797 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1999988813.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1999988803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999994406 + 999994407.

It is an arithmetic number, because the mean of its divisors is an integer number (999994407).

Almost surely, 2^1999988813 is an apocalyptic number.

It is an amenable number.

1999988813 is a deficient number, since it is larger than the sum of its proper divisors (1).

1999988813 is an equidigital number, since it uses as much as digits as its factorization.

1999988813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10077696, while the sum is 65.

The square root of 1999988813 is about 44721.2344753586. The cubic root of 1999988813 is about 1259.9187007677.

The spelling of 1999988813 in words is "one billion, nine hundred ninety-nine million, nine hundred eighty-eight thousand, eight hundred thirteen".