2181344256 has 660 divisors, whose sum is σ = 8516469808. Its totient is φ = 541458432.

The previous prime is 2181344251. The next prime is 2181344281. The reversal of 2181344256 is 6524431812.

It is a happy number.

2181344256 is a `hidden beast` number, since 218 + 13 + 4 + 425 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 2181344256.

It is not an unprimeable number, because it can be changed into a prime (2181344251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 128314360 + ... + 128314376.

Almost surely, 2^2181344256 is an apocalyptic number.

2181344256 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2181344256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4258234904).

2181344256 is an abundant number, since it is smaller than the sum of its proper divisors (6335125552).

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

2181344256 is a wasteful number, since it uses less digits than its factorization.

2181344256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86 (or 42 counting only the distinct ones).

The product of its digits is 46080, while the sum is 36.

The square root of 2181344256 is about 46704.8633013737. The cubic root of 2181344256 is about 1296.9047180772.

The spelling of 2181344256 in words is "two billion, one hundred eighty-one million, three hundred forty-four thousand, two hundred fifty-six".