2101221100 has 144 divisors (see below), whose sum is σ = 5187168000. Its totient is φ = 731808000.

The previous prime is 2101221047. The next prime is 2101221107. The reversal of 2101221100 is 11221012.

It is a super-2 number, since 2×2101221100² = 8830260222170420000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is not an unprimeable number, because it can be changed into a prime (2101221107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6347935 + ... + 6348265.

It is an arithmetic number, because the mean of its divisors is an integer number (36022000).

Almost surely, 2^2101221100 is an apocalyptic number.

2101221100 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 2101221100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2593584000).

2101221100 is an abundant number, since it is smaller than the sum of its proper divisors (3085946900).

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

2101221100 is a wasteful number, since it uses less digits than its factorization.

2101221100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 584 (or 577 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 2101221100 is about 45839.0783066152. The cubic root of 2101221100 is about 1280.8273256587.

Adding to 2101221100 its reverse (11221012), we get a palindrome (2112442112).

The spelling of 2101221100 in words is "two billion, one hundred one million, two hundred twenty-one thousand, one hundred".