2102222120021 has 4 divisors (see below), whose sum is σ = 2105767183212. Its totient is φ = 2098677056832.

The previous prime is 2102222120017. The next prime is 2102222120083. The reversal of 2102222120021 is 1200212222012.

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 626811057796 + 1475411062225 = 791714^2 + 1214665^2 .

It is a cyclic number.

It is not a de Polignac number, because 2102222120021 - 2² = 2102222120017 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2102222180021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1772530706 + ... + 1772531891.

It is an arithmetic number, because the mean of its divisors is an integer number (526441795803).

Almost surely, 2^{2102222120021} is an apocalyptic number.

It is an amenable number.

2102222120021 is a deficient number, since it is larger than the sum of its proper divisors (3545063191).

2102222120021 is an equidigital number, since it uses as much as digits as its factorization.

2102222120021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3545063190.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 2102222120021 its reverse (1200212222012), we get a palindrome (3302434342033).

The spelling of 2102222120021 in words is "two trillion, one hundred two billion, two hundred twenty-two million, one hundred twenty thousand, twenty-one".