20212221100221 has 12 divisors (see below), whose sum is σ = 29200225339740. Its totient is φ = 13472601053760.

The previous prime is 20212221100207. The next prime is 20212221100289. The reversal of 20212221100221 is 12200112221202.

It is a happy number.

20212221100221 is a `hidden beast` number, since 2 + 0 + 212 + 221 + 10 + 0 + 221 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 13367352387321 + 6844868712900 = 3656139^2 + 2616270^2 .

It is not a de Polignac number, because 20212221100221 - 2⁶ = 20212221100157 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20212221100194 and 20212221100203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20212221100121) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 184359910 + ... + 184469511.

It is an arithmetic number, because the mean of its divisors is an integer number (2433352111645).

Almost surely, 2^{20212221100221} is an apocalyptic number.

It is an amenable number.

20212221100221 is a deficient number, since it is larger than the sum of its proper divisors (8988004239519).

20212221100221 is a wasteful number, since it uses less digits than its factorization.

20212221100221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 368835516 (or 368835513 counting only the distinct ones).

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

Adding to 20212221100221 its reverse (12200112221202), we get a palindrome (32412333321423).

The spelling of 20212221100221 in words is "twenty trillion, two hundred twelve billion, two hundred twenty-one million, one hundred thousand, two hundred twenty-one".