2011221220100 has 72 divisors (see below), whose sum is σ = 4472361016200. Its totient is φ = 784592358400.

The previous prime is 2011221220097. The next prime is 2011221220109. The reversal of 2011221220100 is 10221221102.

It can be written as a sum of positive squares in 12 ways, for example, as 147007829056 + 1864213391044 = 383416^2 + 1365362^2 .

It is not an unprimeable number, because it can be changed into a prime (2011221220109) 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, 11842586 + ... + 12011214.

It is an arithmetic number, because the mean of its divisors is an integer number (62116125225).

Almost surely, 2^{2011221220100} is an apocalyptic number.

2011221220100 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 2011221220100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2236180508100).

2011221220100 is an abundant number, since it is smaller than the sum of its proper divisors (2461139796100).

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

2011221220100 is a wasteful number, since it uses less digits than its factorization.

2011221220100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171593 (or 171586 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 2011221220100 its reverse (10221221102), we get a palindrome (2021442441202).

The spelling of 2011221220100 in words is "two trillion, eleven billion, two hundred twenty-one million, two hundred twenty thousand, one hundred".