216641717 has 2 divisors, whose sum is σ = 216641718. Its totient is φ = 216641716.

The previous prime is 216641713. The next prime is 216641729. The reversal of 216641717 is 717146612.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 208109476 + 8532241 = 14426^2 + 2921^2 .

It is a cyclic number.

It is not a de Polignac number, because 216641717 - 2² = 216641713 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216641713) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108320858 + 108320859.

It is an arithmetic number, because the mean of its divisors is an integer number (108320859).

Almost surely, 2^216641717 is an apocalyptic number.

It is an amenable number.

216641717 is a deficient number, since it is larger than the sum of its proper divisors (1).

216641717 is an equidigital number, since it uses as much as digits as its factorization.

216641717 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14112, while the sum is 35.

The square root of 216641717 is about 14718.7539214432. The cubic root of 216641717 is about 600.5935949555.

The spelling of 216641717 in words is "two hundred sixteen million, six hundred forty-one thousand, seven hundred seventeen".