21022221220100 has 72 divisors (see below), whose sum is σ = 45707882898888. Its totient is φ = 8392376678400.

The previous prime is 21022221220057. The next prime is 21022221220109. The reversal of 21022221220100 is 102212222012.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 19627894794244 + 1394326425856 = 4430338^2 + 1180816^2 .

It is not an unprimeable number, because it can be changed into a prime (21022221220109) 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, 106766942 + ... + 106963658.

It is an arithmetic number, because the mean of its divisors is an integer number (634831706929).

Almost surely, 2^{21022221220100} is an apocalyptic number.

21022221220100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21022221220100 is an abundant number, since it is smaller than the sum of its proper divisors (24685661678788).

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

21022221220100 is a wasteful number, since it uses less digits than its factorization.

21022221220100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198825 (or 198818 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21022221220100 its reverse (102212222012), we get a palindrome (21124433442112).

The spelling of 21022221220100 in words is "twenty-one trillion, twenty-two billion, two hundred twenty-one million, two hundred twenty thousand, one hundred".