218114541554821 has 2 divisors, whose sum is σ = 218114541554822. Its totient is φ = 218114541554820.

The previous prime is 218114541554699. The next prime is 218114541554827. The reversal of 218114541554821 is 128455145411812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 153293766766596 + 64820774788225 = 12381186^2 + 8051135^2 .

It is a cyclic number.

It is not a de Polignac number, because 218114541554821 - 2¹⁷ = 218114541423749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (218114541554827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109057270777410 + 109057270777411.

It is an arithmetic number, because the mean of its divisors is an integer number (109057270777411).

Almost surely, 2^{218114541554821} is an apocalyptic number.

It is an amenable number.

218114541554821 is a deficient number, since it is larger than the sum of its proper divisors (1).

218114541554821 is an equidigital number, since it uses as much as digits as its factorization.

218114541554821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2048000, while the sum is 52.

The spelling of 218114541554821 in words is "two hundred eighteen trillion, one hundred fourteen billion, five hundred forty-one million, five hundred fifty-four thousand, eight hundred twenty-one".