2181331680 has 192 divisors, whose sum is σ = 7557193728. Its totient is φ = 524482560.

The previous prime is 2181331609. The next prime is 2181331699. The reversal of 2181331680 is 861331812.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

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 31 ways as a sum of consecutive naturals, for example, 668934 + ... + 672186.

It is an arithmetic number, because the mean of its divisors is an integer number (39360384).

Almost surely, 2^2181331680 is an apocalyptic number.

2181331680 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 2181331680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3778596864).

2181331680 is an abundant number, since it is smaller than the sum of its proper divisors (5375862048).

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

2181331680 is a wasteful number, since it uses less digits than its factorization.

2181331680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3409 (or 3401 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 2181331680 is about 46704.7286685192. The cubic root of 2181331680 is about 1296.9022257448.

The spelling of 2181331680 in words is "two billion, one hundred eighty-one million, three hundred thirty-one thousand, six hundred eighty".