21222220100 has 72 divisors (see below), whose sum is σ = 46497024000. Its totient is φ = 8407302400.

The previous prime is 21222220099. The next prime is 21222220109. The reversal of 21222220100 is 102222212.

It is not an unprimeable number, because it can be changed into a prime (21222220109) 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, 4562576 + ... + 4567224.

It is an arithmetic number, because the mean of its divisors is an integer number (645792000).

Almost surely, 2^21222220100 is an apocalyptic number.

21222220100 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 21222220100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23248512000).

21222220100 is an abundant number, since it is smaller than the sum of its proper divisors (25274803900).

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

21222220100 is a wasteful number, since it uses less digits than its factorization.

21222220100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5093 (or 5086 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 21222220100 its reverse (102222212), we get a palindrome (21324442312).

It can be divided in two parts, 2122 and 2220100, that added together give a palindrome (2222222).

The spelling of 21222220100 in words is "twenty-one billion, two hundred twenty-two million, two hundred twenty thousand, one hundred".