21201101220100 has 18 divisors (see below), whose sum is σ = 46006389647834. Its totient is φ = 8480440488000.

The previous prime is 21201101220083. The next prime is 21201101220107. The reversal of 21201101220100 is 102210110212.

It can be written as a sum of positive squares in 3 ways, for example, as 295503134404 + 20905598085696 = 543602^2 + 4572264^2 .

It is not an unprimeable number, because it can be changed into a prime (21201101220107) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 106005506001 + ... + 106005506200.

Almost surely, 2^{21201101220100} is an apocalyptic number.

21201101220100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21201101220100 is an abundant number, since it is smaller than the sum of its proper divisors (24805288427734).

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

21201101220100 is a wasteful number, since it uses less digits than its factorization.

21201101220100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212011012215 (or 212011012208 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21201101220100 its reverse (102210110212), we get a palindrome (21303311330312).

The spelling of 21201101220100 in words is "twenty-one trillion, two hundred one billion, one hundred one million, two hundred twenty thousand, one hundred".