218121826056 has 128 divisors (see below), whose sum is σ = 574130229120. Its totient is φ = 68979216384.

The previous prime is 218121826007. The next prime is 218121826063. The reversal of 218121826056 is 650628121812.

It is a junction number, because it is equal to n+sod(n) for n = 218121825999 and 218121826017.

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 31 ways as a sum of consecutive naturals, for example, 7657216 + ... + 7685648.

It is an arithmetic number, because the mean of its divisors is an integer number (4485392415).

Almost surely, 2^218121826056 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 218121826056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (287065114560).

218121826056 is an abundant number, since it is smaller than the sum of its proper divisors (356008403064).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

218121826056 is a wasteful number, since it uses less digits than its factorization.

218121826056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28695 (or 28691 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 42.

Adding to 218121826056 its reverse (650628121812), we get a palindrome (868749947868).

The spelling of 218121826056 in words is "two hundred eighteen billion, one hundred twenty-one million, eight hundred twenty-six thousand, fifty-six".