2221111021 has 2 divisors, whose sum is σ = 2221111022. Its totient is φ = 2221111020.

The previous prime is 2221111019. The next prime is 2221111027. The reversal of 2221111021 is 1201111222.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1727649225 + 493461796 = 41565^2 + 22214^2 .

It is a cyclic number.

It is not a de Polignac number, because 2221111021 - 2¹ = 2221111019 is a prime.

Together with 2221111019, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 2221110992 and 2221111010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2221111027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1110555510 + 1110555511.

It is an arithmetic number, because the mean of its divisors is an integer number (1110555511).

Almost surely, 2^2221111021 is an apocalyptic number.

It is an amenable number.

2221111021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2221111021 is an equidigital number, since it uses as much as digits as its factorization.

2221111021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 13.

The square root of 2221111021 is about 47128.6645365642. The cubic root of 2221111021 is about 1304.7383338395.

Adding to 2221111021 its reverse (1201111222), we get a palindrome (3422222243).

The spelling of 2221111021 in words is "two billion, two hundred twenty-one million, one hundred eleven thousand, twenty-one".