2181225618 has 96 divisors (see below), whose sum is σ = 5737939200. Its totient is φ = 610109280.

The previous prime is 2181225601. The next prime is 2181225643. The reversal of 2181225618 is 8165221812.

2181225618 is a `hidden beast` number, since 2 + 1 + 8 + 12 + 25 + 618 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 72103 + ... + 97781.

It is an arithmetic number, because the mean of its divisors is an integer number (59770200).

Almost surely, 2^2181225618 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2181225618, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2868969600).

2181225618 is an abundant number, since it is smaller than the sum of its proper divisors (3556713582).

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

2181225618 is a wasteful number, since it uses less digits than its factorization.

2181225618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25725 (or 25708 counting only the distinct ones).

The product of its digits is 15360, while the sum is 36.

The square root of 2181225618 is about 46703.5932022366. The cubic root of 2181225618 is about 1296.8812058216.

The spelling of 2181225618 in words is "two billion, one hundred eighty-one million, two hundred twenty-five thousand, six hundred eighteen".