221201212002100 has 54 divisors (see below), whose sum is σ = 527610593383622. Its totient is φ = 80436804360000.

The previous prime is 221201212002077. The next prime is 221201212002103. The reversal of 221201212002100 is 1200212102122.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 3544950902416 + 217656261099684 = 1882804^2 + 14753178^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221201212002103) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 9140533851 + ... + 9140558050.

Almost surely, 2^{221201212002100} is an apocalyptic number.

221201212002100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221201212002100 is an abundant number, since it is smaller than the sum of its proper divisors (306409381381522).

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

221201212002100 is a wasteful number, since it uses less digits than its factorization.

221201212002100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18281091937 (or 18281091919 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 221201212002100 its reverse (1200212102122), we get a palindrome (222401424104222).

The spelling of 221201212002100 in words is "two hundred twenty-one trillion, two hundred one billion, two hundred twelve million, two thousand, one hundred".