2221021021 has 4 divisors (see below), whose sum is σ = 2262927132. Its totient is φ = 2179114912.

The previous prime is 2221021003. The next prime is 2221021027. The reversal of 2221021021 is 1201201222.

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 1280924100 + 940096921 = 35790^2 + 30661^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2221021021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2221020992 and 2221021010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2221021027) 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, 20952976 + ... + 20953081.

It is an arithmetic number, because the mean of its divisors is an integer number (565731783).

Almost surely, 2^2221021021 is an apocalyptic number.

It is an amenable number.

2221021021 is a deficient number, since it is larger than the sum of its proper divisors (41906111).

2221021021 is an equidigital number, since it uses as much as digits as its factorization.

2221021021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41906110.

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

The square root of 2221021021 is about 47127.7096939794. The cubic root of 2221021021 is about 1304.7207108219.

Adding to 2221021021 its reverse (1201201222), we get a palindrome (3422222243).

The spelling of 2221021021 in words is "two billion, two hundred twenty-one million, twenty-one thousand, twenty-one".