2181228404256 has 288 divisors, whose sum is σ = 6824486934720. Its totient is φ = 655361280000.

The previous prime is 2181228404239. The next prime is 2181228404263. The reversal of 2181228404256 is 6524048221812.

It is a happy number.

2181228404256 is a `hidden beast` number, since 2 + 18 + 1 + 228 + 404 + 2 + 5 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 207711006 + ... + 207721506.

It is an arithmetic number, because the mean of its divisors is an integer number (23696135190).

Almost surely, 2^{2181228404256} 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 2181228404256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3412243467360).

2181228404256 is an abundant number, since it is smaller than the sum of its proper divisors (4643258530464).

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

2181228404256 is a wasteful number, since it uses less digits than its factorization.

2181228404256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11080 (or 11069 counting only the distinct ones).

The product of its (nonzero) digits is 491520, while the sum is 45.

The spelling of 2181228404256 in words is "two trillion, one hundred eighty-one billion, two hundred twenty-eight million, four hundred four thousand, two hundred fifty-six".