2221221211021 has 4 divisors (see below), whose sum is σ = 2221863000444. Its totient is φ = 2220579421600.

The previous prime is 2221221210997. The next prime is 2221221211031. The reversal of 2221221211021 is 1201121221222.

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 1552301695396 + 668919515625 = 1245914^2 + 817875^2 .

It is a cyclic number.

It is not a de Polignac number, because 2221221211021 - 2¹⁹ = 2221220686733 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2221221211021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2221221211031) 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, 320889520 + ... + 320896441.

It is an arithmetic number, because the mean of its divisors is an integer number (555465750111).

Almost surely, 2^{2221221211021} is an apocalyptic number.

It is an amenable number.

2221221211021 is a deficient number, since it is larger than the sum of its proper divisors (641789423).

2221221211021 is an equidigital number, since it uses as much as digits as its factorization.

2221221211021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 641789422.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 2221221211021 its reverse (1201121221222), we get a palindrome (3422342432243).

The spelling of 2221221211021 in words is "two trillion, two hundred twenty-one billion, two hundred twenty-one million, two hundred eleven thousand, twenty-one".