217989797699 has 2 divisors, whose sum is σ = 217989797700. Its totient is φ = 217989797698.

The previous prime is 217989797671. The next prime is 217989797719. The reversal of 217989797699 is 996797989712.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-217989797699 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (217989797299) 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, 108994898849 + 108994898850.

It is an arithmetic number, because the mean of its divisors is an integer number (108994898850).

Almost surely, 2^217989797699 is an apocalyptic number.

217989797699 is a deficient number, since it is larger than the sum of its proper divisors (1).

217989797699 is an equidigital number, since it uses as much as digits as its factorization.

217989797699 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1944365472, while the sum is 83.

The spelling of 217989797699 in words is "two hundred seventeen billion, nine hundred eighty-nine million, seven hundred ninety-seven thousand, six hundred ninety-nine".