217800666613 has 2 divisors, whose sum is σ = 217800666614. Its totient is φ = 217800666612.

The previous prime is 217800666599. The next prime is 217800666647. The reversal of 217800666613 is 316666008712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 108938283364 + 108862383249 = 330058^2 + 329943^2 .

It is a cyclic number.

It is not a de Polignac number, because 217800666613 - 2¹⁷ = 217800535541 is a prime.

It is a super-3 number, since 3×217800666613³ (a number of 35 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (217800666653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108900333306 + 108900333307.

It is an arithmetic number, because the mean of its divisors is an integer number (108900333307).

Almost surely, 2^217800666613 is an apocalyptic number.

It is an amenable number.

217800666613 is a deficient number, since it is larger than the sum of its proper divisors (1).

217800666613 is an equidigital number, since it uses as much as digits as its factorization.

217800666613 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 435456, while the sum is 46.

The spelling of 217800666613 in words is "two hundred seventeen billion, eight hundred million, six hundred sixty-six thousand, six hundred thirteen".