9998199917 has 2 divisors, whose sum is σ = 9998199918. Its totient is φ = 9998199916.

The previous prime is 9998199881. The next prime is 9998199943. The reversal of 9998199917 is 7199918999.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9891098116 + 107101801 = 99454^2 + 10349^2 .

It is a cyclic number.

It is not a de Polignac number, because 9998199917 - 2⁸ = 9998199661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9998199217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4999099958 + 4999099959.

It is an arithmetic number, because the mean of its divisors is an integer number (4999099959).

Almost surely, 2^9998199917 is an apocalyptic number.

It is an amenable number.

9998199917 is a deficient number, since it is larger than the sum of its proper divisors (1).

9998199917 is an equidigital number, since it uses as much as digits as its factorization.

9998199917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 29760696, while the sum is 71.

The square root of 9998199917 is about 99990.9991799262. Note that the first 3 decimals coincide. The cubic root of 9998199917 is about 2154.3054102324.

The spelling of 9998199917 in words is "nine billion, nine hundred ninety-eight million, one hundred ninety-nine thousand, nine hundred seventeen".