2181221700 has 144 divisors (see below), whose sum is σ = 7226870784. Its totient is φ = 497577600.

The previous prime is 2181221699. The next prime is 2181221759. The reversal of 2181221700 is 71221812.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1862115 + ... + 1863285.

Almost surely, 2^2181221700 is an apocalyptic number.

2181221700 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 2181221700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3613435392).

2181221700 is an abundant number, since it is smaller than the sum of its proper divisors (5045649084).

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

2181221700 is a wasteful number, since it uses less digits than its factorization.

2181221700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2082 (or 2075 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 24.

The square root of 2181221700 is about 46703.5512568370. The cubic root of 2181221700 is about 1296.8804293187.

The spelling of 2181221700 in words is "two billion, one hundred eighty-one million, two hundred twenty-one thousand, seven hundred".