2021201221 has 4 divisors (see below), whose sum is σ = 2176678252. Its totient is φ = 1865724192.

The previous prime is 2021201177. The next prime is 2021201249. The reversal of 2021201221 is 1221021202.

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 1226750625 + 794450596 = 35025^2 + 28186^2 .

It is a cyclic number.

It is not a de Polignac number, because 2021201221 - 2²⁵ = 1987646789 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13), and also a Moran number because the ratio is a prime number: 155477017 = 2021201221 / (2 + 0 + 2 + 1 + 2 + 0 + 1 + 2 + 2 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021201821) 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, 77738496 + ... + 77738521.

It is an arithmetic number, because the mean of its divisors is an integer number (544169563).

Almost surely, 2^2021201221 is an apocalyptic number.

It is an amenable number.

2021201221 is a deficient number, since it is larger than the sum of its proper divisors (155477031).

2021201221 is a wasteful number, since it uses less digits than its factorization.

2021201221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155477030.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 2021201221 is about 44957.7715306264. The cubic root of 2021201221 is about 1264.3573881006.

Adding to 2021201221 its reverse (1221021202), we get a palindrome (3242222423).

The spelling of 2021201221 in words is "two billion, twenty-one million, two hundred one thousand, two hundred twenty-one".