2221020221 has 4 divisors (see below), whose sum is σ = 2538308832. Its totient is φ = 1903731612.

The previous prime is 2221020161. The next prime is 2221020227. The reversal of 2221020221 is 1220201222.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1220201222 = 2 ⋅610100611.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2221020221 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 = 2221020196 and 2221020205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2221020227) 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, 158644295 + ... + 158644308.

It is an arithmetic number, because the mean of its divisors is an integer number (634577208).

Almost surely, 2^2221020221 is an apocalyptic number.

It is an amenable number.

2221020221 is a deficient number, since it is larger than the sum of its proper divisors (317288611).

2221020221 is an equidigital number, since it uses as much as digits as its factorization.

2221020221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 317288610.

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 2221020221 is about 47127.7012064030. The cubic root of 2221020221 is about 1304.7205541707.

Adding to 2221020221 its reverse (1220201222), we get a palindrome (3441221443).

The spelling of 2221020221 in words is "two billion, two hundred twenty-one million, twenty thousand, two hundred twenty-one".