2181100000 has 144 divisors (see below), whose sum is σ = 5687354736. Its totient is φ = 820480000.

The previous prime is 2181099989. The next prime is 2181100007. The reversal of 2181100000 is 11812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2181100007) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1699359 + ... + 1700641.

It is an arithmetic number, because the mean of its divisors is an integer number (39495519).

Almost surely, 2^2181100000 is an apocalyptic number.

2181100000 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 2181100000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2843677368).

2181100000 is an abundant number, since it is smaller than the sum of its proper divisors (3506254736).

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

2181100000 is an equidigital number, since it uses as much as digits as its factorization.

2181100000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1335 (or 1307 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

The square root of 2181100000 is about 46702.2483398819. The cubic root of 2181100000 is about 1296.8563093063.

Adding to 2181100000 its reverse (11812), we get a palindrome (2181111812).

The spelling of 2181100000 in words is "two billion, one hundred eighty-one million, one hundred thousand".