217952689 has 2 divisors, whose sum is σ = 217952690. Its totient is φ = 217952688.

The previous prime is 217952671. The next prime is 217952711. The reversal of 217952689 is 986259712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 147258225 + 70694464 = 12135^2 + 8408^2 .

It is a cyclic number.

It is not a de Polignac number, because 217952689 - 2¹⁵ = 217919921 is a prime.

It is not a weakly prime, because it can be changed into another prime (217952659) 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, 108976344 + 108976345.

It is an arithmetic number, because the mean of its divisors is an integer number (108976345).

Almost surely, 2^217952689 is an apocalyptic number.

It is an amenable number.

217952689 is a deficient number, since it is larger than the sum of its proper divisors (1).

217952689 is an equidigital number, since it uses as much as digits as its factorization.

217952689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 544320, while the sum is 49.

The square root of 217952689 is about 14763.2208206746. The cubic root of 217952689 is about 601.8026241901.

The spelling of 217952689 in words is "two hundred seventeen million, nine hundred fifty-two thousand, six hundred eighty-nine".