201020202121221 has 24 divisors (see below), whose sum is σ = 349308287731520. Its totient is φ = 108822966561216.

The previous prime is 201020202121187. The next prime is 201020202121243. The reversal of 201020202121221 is 122121202020102.

It is a happy number.

201020202121221 is a `hidden beast` number, since 20 + 10 + 202 + 0 + 212 + 1 + 221 = 666.

It is not a de Polignac number, because 201020202121221 - 2¹⁸ = 201020201859077 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 201020202121194 and 201020202121203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201020202121121) 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, 83968337200 + ... + 83968339593.

Almost surely, 2^{201020202121221} is an apocalyptic number.

201020202121221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

201020202121221 is a deficient number, since it is larger than the sum of its proper divisors (148288085610299).

201020202121221 is a wasteful number, since it uses less digits than its factorization.

201020202121221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167936676825 (or 167936676822 counting only the distinct ones).

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

Adding to 201020202121221 its reverse (122121202020102), we get a palindrome (323141404141323).

The spelling of 201020202121221 in words is "two hundred one trillion, twenty billion, two hundred two million, one hundred twenty-one thousand, two hundred twenty-one".