2021221201 has 4 divisors (see below), whose sum is σ = 2021323572. Its totient is φ = 2021118832.

The previous prime is 2021221199. The next prime is 2021221231. The reversal of 2021221201 is 1021221202.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1021221202 = 2 ⋅510610601.

It can be written as a sum of positive squares in 2 ways, for example, as 745017025 + 1276204176 = 27295^2 + 35724^2 .

It is a cyclic number.

It is not a de Polignac number, because 2021221201 - 2¹ = 2021221199 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2021221231) 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, 11110 + ... + 64543.

It is an arithmetic number, because the mean of its divisors is an integer number (505330893).

Almost surely, 2^2021221201 is an apocalyptic number.

It is an amenable number.

2021221201 is a deficient number, since it is larger than the sum of its proper divisors (102371).

2021221201 is an equidigital number, since it uses as much as digits as its factorization.

2021221201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102370.

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

The square root of 2021221201 is about 44957.9937386000. The cubic root of 2021221201 is about 1264.3615542333.

Adding to 2021221201 its reverse (1021221202), we get a palindrome (3042442403).

Subtracting from 2021221201 its reverse (1021221202), we obtain a palindrome (999999999).

The spelling of 2021221201 in words is "two billion, twenty-one million, two hundred twenty-one thousand, two hundred one".