2221221100 has 72 divisors (see below), whose sum is σ = 5575143168. Its totient is φ = 752366400.

The previous prime is 2221221091. The next prime is 2221221103. The reversal of 2221221100 is 11221222.

It is a happy number.

It is a super-4 number, since 4×2221221100⁴ (a number of 38 digits) contains 4444 as substring.

It is not an unprimeable number, because it can be changed into a prime (2221221103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 38985 + ... + 77215.

It is an arithmetic number, because the mean of its divisors is an integer number (77432544).

Almost surely, 2^2221221100 is an apocalyptic number.

2221221100 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 2221221100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2787571584).

2221221100 is an abundant number, since it is smaller than the sum of its proper divisors (3353922068).

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

2221221100 is a wasteful number, since it uses less digits than its factorization.

2221221100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38335 (or 38328 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 2221221100 is about 47129.8323782294. The cubic root of 2221221100 is about 1304.7598879052.

Adding to 2221221100 its reverse (11221222), we get a palindrome (2232442322).

The spelling of 2221221100 in words is "two billion, two hundred twenty-one million, two hundred twenty-one thousand, one hundred".