201221121210221 has 4 divisors (see below), whose sum is σ = 229966995668832. Its totient is φ = 172475246751612.

The previous prime is 201221121210173. The next prime is 201221121210247. The reversal of 201221121210221 is 122012121122102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 201221121210221 - 2⁶ = 201221121210157 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 201221121210193 and 201221121210202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201221121210271) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14372937229295 + ... + 14372937229308.

It is an arithmetic number, because the mean of its divisors is an integer number (57491748917208).

Almost surely, 2^{201221121210221} is an apocalyptic number.

It is an amenable number.

201221121210221 is a deficient number, since it is larger than the sum of its proper divisors (28745874458611).

201221121210221 is an equidigital number, since it uses as much as digits as its factorization.

201221121210221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28745874458610.

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 201221121210221 its reverse (122012121122102), we get a palindrome (323233242332323).

The spelling of 201221121210221 in words is "two hundred one trillion, two hundred twenty-one billion, one hundred twenty-one million, two hundred ten thousand, two hundred twenty-one".