218256821844 has 24 divisors (see below), whose sum is σ = 509415489408. Its totient is φ = 72730906560.

The previous prime is 218256821833. The next prime is 218256821863. The reversal of 218256821844 is 448128652812.

218256821844 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent 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 7 ways as a sum of consecutive naturals, for example, 2628337 + ... + 2710104.

It is an arithmetic number, because the mean of its divisors is an integer number (21225645392).

Almost surely, 2^218256821844 is an apocalyptic number.

It is an amenable number.

218256821844 is an abundant number, since it is smaller than the sum of its proper divisors (291158667564).

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

218256821844 is a wasteful number, since it uses less digits than its factorization.

218256821844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5341855 (or 5341853 counting only the distinct ones).

The product of its digits is 1966080, while the sum is 51.

The spelling of 218256821844 in words is "two hundred eighteen billion, two hundred fifty-six million, eight hundred twenty-one thousand, eight hundred forty-four".