218637506668829 has 2 divisors, whose sum is σ = 218637506668830. Its totient is φ = 218637506668828.

The previous prime is 218637506668813. The next prime is 218637506668849. The reversal of 218637506668829 is 928866605736812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 176417102484100 + 42220404184729 = 13282210^2 + 6497723^2 .

It is a cyclic number.

It is not a de Polignac number, because 218637506668829 - 2⁴ = 218637506668813 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 218637506668829.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (218637506668849) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109318753334414 + 109318753334415.

It is an arithmetic number, because the mean of its divisors is an integer number (109318753334415).

Almost surely, 2^{218637506668829} is an apocalyptic number.

It is an amenable number.

218637506668829 is a deficient number, since it is larger than the sum of its proper divisors (1).

218637506668829 is an equidigital number, since it uses as much as digits as its factorization.

218637506668829 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2508226560, while the sum is 77.

The spelling of 218637506668829 in words is "two hundred eighteen trillion, six hundred thirty-seven billion, five hundred six million, six hundred sixty-eight thousand, eight hundred twenty-nine".