201220211221 has 4 divisors (see below), whose sum is σ = 213056694252. Its totient is φ = 189383728192.

The previous prime is 201220211209. The next prime is 201220211239. The reversal of 201220211221 is 122112022102.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 170766471121 + 30453740100 = 413239^2 + 174510^2 .

It is a cyclic number.

It is not a de Polignac number, because 201220211221 - 2³⁵ = 166860472853 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 201220211195 and 201220211204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201220211201) 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, 5918241490 + ... + 5918241523.

It is an arithmetic number, because the mean of its divisors is an integer number (53264173563).

Almost surely, 2^201220211221 is an apocalyptic number.

It is an amenable number.

201220211221 is a deficient number, since it is larger than the sum of its proper divisors (11836483031).

201220211221 is a wasteful number, since it uses less digits than its factorization.

201220211221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11836483030.

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

Adding to 201220211221 its reverse (122112022102), we get a palindrome (323332233323).

The spelling of 201220211221 in words is "two hundred one billion, two hundred twenty million, two hundred eleven thousand, two hundred twenty-one".