1999915117 has 2 divisors, whose sum is σ = 1999915118. Its totient is φ = 1999915116.

The previous prime is 1999915109. The next prime is 1999915133. The reversal of 1999915117 is 7115199991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1968341956 + 31573161 = 44366^2 + 5619^2 .

It is a cyclic number.

It is not a de Polignac number, because 1999915117 - 2³ = 1999915109 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1999915217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999957558 + 999957559.

It is an arithmetic number, because the mean of its divisors is an integer number (999957559).

Almost surely, 2^1999915117 is an apocalyptic number.

It is an amenable number.

1999915117 is a deficient number, since it is larger than the sum of its proper divisors (1).

1999915117 is an equidigital number, since it uses as much as digits as its factorization.

1999915117 is an evil number, because the sum of its binary digits is even.

The product of its digits is 229635, while the sum is 52.

The square root of 1999915117 is about 44720.4105191354. The cubic root of 1999915117 is about 1259.9032253296.

The spelling of 1999915117 in words is "one billion, nine hundred ninety-nine million, nine hundred fifteen thousand, one hundred seventeen".