218637506668811 has 2 divisors, whose sum is σ = 218637506668812. Its totient is φ = 218637506668810.

The previous prime is 218637506668759. The next prime is 218637506668813. The reversal of 218637506668811 is 118866605736812.

218637506668811 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 218637506668811 - 2⁴² = 214239460157707 is a prime.

Together with 218637506668813, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (218637506668813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109318753334405 + 109318753334406.

It is an arithmetic number, because the mean of its divisors is an integer number (109318753334406).

Almost surely, 2^{218637506668811} is an apocalyptic number.

218637506668811 is a deficient number, since it is larger than the sum of its proper divisors (1).

218637506668811 is an equidigital number, since it uses as much as digits as its factorization.

218637506668811 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 139345920, while the sum is 68.

The spelling of 218637506668811 in words is "two hundred eighteen trillion, six hundred thirty-seven billion, five hundred six million, six hundred sixty-eight thousand, eight hundred eleven".