218522638418 has 18 divisors (see below), whose sum is σ = 381307780773. Its totient is φ = 93650576040.

The previous prime is 218522638387. The next prime is 218522638471. The reversal of 218522638418 is 814836225812.

218522638418 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 197014362769 + 21508275649 = 443863^2 + 146657^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=330547.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 4604048 + ... + 4651268.

Almost surely, 2^218522638418 is an apocalyptic number.

218522638418 is a deficient number, since it is larger than the sum of its proper divisors (162785142355).

218522638418 is an frugal number, since it uses more digits than its factorization.

218522638418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94458 (or 47230 counting only the distinct ones).

The product of its digits is 1474560, while the sum is 50.

Multiplying 218522638418 by its sum of digits (50), we get a square (10926131920900 = 3305470²).

The spelling of 218522638418 in words is "two hundred eighteen billion, five hundred twenty-two million, six hundred thirty-eight thousand, four hundred eighteen".