218842661845 has 8 divisors (see below), whose sum is σ = 262634815800. Its totient is φ = 175058381760.

The previous prime is 218842661783. The next prime is 218842661927. The reversal of 218842661845 is 548166248812.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3389801284 + 215452860561 = 58222^2 + 464169^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 218842661845 - 2²¹ = 218840564693 is a prime.

It is a super-2 number, since 2×218842661845² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1907146 + ... + 2018635.

It is an arithmetic number, because the mean of its divisors is an integer number (32829351975).

Almost surely, 2^218842661845 is an apocalyptic number.

It is an amenable number.

218842661845 is a deficient number, since it is larger than the sum of its proper divisors (43792153955).

218842661845 is a wasteful number, since it uses less digits than its factorization.

218842661845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3936935.

The product of its digits is 5898240, while the sum is 55.

The spelling of 218842661845 in words is "two hundred eighteen billion, eight hundred forty-two million, six hundred sixty-one thousand, eight hundred forty-five".