2181328380 has 672 divisors, whose sum is σ = 8990231040. Its totient is φ = 431101440.

The previous prime is 2181328379. The next prime is 2181328393. The reversal of 2181328380 is 838231812.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 223 ways as a sum of consecutive naturals, for example, 32557107 + ... + 32557173.

It is an arithmetic number, because the mean of its divisors is an integer number (13378320).

Almost surely, 2^2181328380 is an apocalyptic number.

2181328380 is a gapful number since it is divisible by the number (20) 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 2181328380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4495115520).

2181328380 is an abundant number, since it is smaller than the sum of its proper divisors (6808902660).

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

2181328380 is a wasteful number, since it uses less digits than its factorization.

2181328380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141 (or 124 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 2181328380 is about 46704.6933401773. The cubic root of 2181328380 is about 1296.9015717438.

The spelling of 2181328380 in words is "two billion, one hundred eighty-one million, three hundred twenty-eight thousand, three hundred eighty".