218000266834661 has 4 divisors (see below), whose sum is σ = 218687964837612. Its totient is φ = 217312568831712.

The previous prime is 218000266834619. The next prime is 218000266834663. The reversal of 218000266834661 is 166438662000812.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12241496476225 + 205758770358436 = 3498785^2 + 14344294^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-218000266834661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218000266834663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 343849001000 + ... + 343849001633.

It is an arithmetic number, because the mean of its divisors is an integer number (54671991209403).

Almost surely, 2^{218000266834661} is an apocalyptic number.

It is an amenable number.

218000266834661 is a deficient number, since it is larger than the sum of its proper divisors (687698002951).

218000266834661 is an equidigital number, since it uses as much as digits as its factorization.

218000266834661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 687698002950.

The product of its (nonzero) digits is 3981312, while the sum is 53.

The spelling of 218000266834661 in words is "two hundred eighteen trillion, two hundred sixty-six million, eight hundred thirty-four thousand, six hundred sixty-one".