2211221021 has 4 divisors (see below), whose sum is σ = 2234017212. Its totient is φ = 2188424832.

The previous prime is 2211220997. The next prime is 2211221039. The reversal of 2211221021 is 1201221122.

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 826562500 + 1384658521 = 28750^2 + 37211^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2211221021 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 = 2211220987 and 2211221005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2211227021) 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, 11397950 + ... + 11398143.

It is an arithmetic number, because the mean of its divisors is an integer number (558504303).

Almost surely, 2^2211221021 is an apocalyptic number.

It is an amenable number.

2211221021 is a deficient number, since it is larger than the sum of its proper divisors (22796191).

2211221021 is an equidigital number, since it uses as much as digits as its factorization.

2211221021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22796190.

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 2211221021 is about 47023.6219468471. The cubic root of 2211221021 is about 1302.7989047317.

Adding to 2211221021 its reverse (1201221122), we get a palindrome (3412442143).

The spelling of 2211221021 in words is "two billion, two hundred eleven million, two hundred twenty-one thousand, twenty-one".