218898656186081 has 2 divisors, whose sum is σ = 218898656186082. Its totient is φ = 218898656186080.

The previous prime is 218898656186009. The next prime is 218898656186087. The reversal of 218898656186081 is 180681656898812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 218637151795456 + 261504390625 = 14786384^2 + 511375^2 .

It is a cyclic number.

It is not a de Polignac number, because 218898656186081 - 2⁴⁶ = 148529912008417 is a prime.

It is a super-2 number, since 2×218898656186081² (a number of 29 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 218898656185993 and 218898656186011.

It is not a weakly prime, because it can be changed into another prime (218898656186087) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109449328093040 + 109449328093041.

It is an arithmetic number, because the mean of its divisors is an integer number (109449328093041).

Almost surely, 2^{218898656186081} is an apocalyptic number.

It is an amenable number.

218898656186081 is a deficient number, since it is larger than the sum of its proper divisors (1).

218898656186081 is an equidigital number, since it uses as much as digits as its factorization.

218898656186081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 637009920, while the sum is 77.

The spelling of 218898656186081 in words is "two hundred eighteen trillion, eight hundred ninety-eight billion, six hundred fifty-six million, one hundred eighty-six thousand, eighty-one".