21201200212100 has 18 divisors (see below), whose sum is σ = 46006604460474. Its totient is φ = 8480480084800.

The previous prime is 21201200212081. The next prime is 21201200212151. The reversal of 21201200212100 is 121200210212.

It can be written as a sum of positive squares in 3 ways, for example, as 210269936704 + 20990930275396 = 458552^2 + 4581586^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 106006000961 + ... + 106006001160.

Almost surely, 2^{21201200212100} is an apocalyptic number.

21201200212100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21201200212100 is an abundant number, since it is smaller than the sum of its proper divisors (24805404248374).

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

21201200212100 is a wasteful number, since it uses less digits than its factorization.

21201200212100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212012002135 (or 212012002128 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21201200212100 its reverse (121200210212), we get a palindrome (21322400422312).

The spelling of 21201200212100 in words is "twenty-one trillion, two hundred one billion, two hundred million, two hundred twelve thousand, one hundred".