1999997117 has 2 divisors, whose sum is σ = 1999997118. Its totient is φ = 1999997116.

The previous prime is 1999997107. The next prime is 1999997141. The reversal of 1999997117 is 7117999991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1142034436 + 857962681 = 33794^2 + 29291^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1999997117 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1999997117.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1999997107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999998558 + 999998559.

It is an arithmetic number, because the mean of its divisors is an integer number (999998559).

Almost surely, 2^1999997117 is an apocalyptic number.

It is an amenable number.

1999997117 is a deficient number, since it is larger than the sum of its proper divisors (1).

1999997117 is an equidigital number, since it uses as much as digits as its factorization.

1999997117 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2893401, while the sum is 62.

The square root of 1999997117 is about 44721.3273170643. The cubic root of 1999997117 is about 1259.9204445025.

The spelling of 1999997117 in words is "one billion, nine hundred ninety-nine million, nine hundred ninety-seven thousand, one hundred seventeen".