21222121220100 has 108 divisors (see below), whose sum is σ = 66927655880176. Its totient is φ = 5624513069760.

The previous prime is 21222121220081. The next prime is 21222121220101. The reversal of 21222121220100 is 102212122212.

It is a happy number.

21222121220100 is a `hidden beast` number, since 2 + 1 + 222 + 121 + 220 + 100 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21222121220101) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 72185002 + ... + 72478401.

Almost surely, 2^{21222121220100} is an apocalyptic number.

21222121220100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21222121220100 is an abundant number, since it is smaller than the sum of its proper divisors (45705534660076).

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

21222121220100 is a wasteful number, since it uses less digits than its factorization.

21222121220100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144663586 (or 144663576 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21222121220100 its reverse (102212122212), we get a palindrome (21324333342312).

The spelling of 21222121220100 in words is "twenty-one trillion, two hundred twenty-two billion, one hundred twenty-one million, two hundred twenty thousand, one hundred".