1999991113 has 2 divisors, whose sum is σ = 1999991114. Its totient is φ = 1999991112.

The previous prime is 1999991099. The next prime is 1999991131. The reversal of 1999991113 is 3111999991.

Together with next prime (1999991131) 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., 1912137984 + 87853129 = 43728^2 + 9373^2 .

It is a cyclic number.

It is not a de Polignac number, because 1999991113 - 2²⁹ = 1463120201 is a prime.

It is not a weakly prime, because it can be changed into another prime (1999991153) 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, 999995556 + 999995557.

It is an arithmetic number, because the mean of its divisors is an integer number (999995557).

Almost surely, 2^1999991113 is an apocalyptic number.

It is an amenable number.

1999991113 is a deficient number, since it is larger than the sum of its proper divisors (1).

1999991113 is an equidigital number, since it uses as much as digits as its factorization.

1999991113 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 177147, while the sum is 52.

The square root of 1999991113 is about 44721.2601902048. The cubic root of 1999991113 is about 1259.9191837390.

The spelling of 1999991113 in words is "one billion, nine hundred ninety-nine million, nine hundred ninety-one thousand, one hundred thirteen".