218088790656 has 128 divisors (see below), whose sum is σ = 638478106560. Its totient is φ = 65406074880.

The previous prime is 218088790609. The next prime is 218088790687. The reversal of 218088790656 is 656097880812.

It is a tau number, because it is divible by the number of its divisors (128).

It is a self number, because there is not a number n which added to its sum of digits gives 218088790656.

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 15 ways as a sum of consecutive naturals, for example, 143590 + ... + 675866.

Almost surely, 2^218088790656 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 218088790656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (319239053280).

218088790656 is an abundant number, since it is smaller than the sum of its proper divisors (420389315904).

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

218088790656 is a wasteful number, since it uses less digits than its factorization.

218088790656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 532402 (or 532390 counting only the distinct ones).

The product of its (nonzero) digits is 11612160, while the sum is 60.

The spelling of 218088790656 in words is "two hundred eighteen billion, eighty-eight million, seven hundred ninety thousand, six hundred fifty-six".