221100221122021 has 4 divisors (see below), whose sum is σ = 221110508224012. Its totient is φ = 221089934020032.

The previous prime is 221100221122019. The next prime is 221100221122093. The reversal of 221100221122021 is 120221122001122.

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 80265275709921 + 140834945412100 = 8959089^2 + 11867390^2 .

It is a cyclic number.

It is not a de Polignac number, because 221100221122021 - 2¹ = 221100221122019 is a prime.

It is a super-2 number, since 2×221100221122021² (a number of 29 digits) contains 22 as substring.

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 221100221122021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221100221122421) 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, 5143518756 + ... + 5143561741.

It is an arithmetic number, because the mean of its divisors is an integer number (55277627056003).

Almost surely, 2^{221100221122021} is an apocalyptic number.

It is an amenable number.

221100221122021 is a deficient number, since it is larger than the sum of its proper divisors (10287101991).

221100221122021 is a wasteful number, since it uses less digits than its factorization.

221100221122021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10287101990.

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

Adding to 221100221122021 its reverse (120221122001122), we get a palindrome (341321343123143).

The spelling of 221100221122021 in words is "two hundred twenty-one trillion, one hundred billion, two hundred twenty-one million, one hundred twenty-two thousand, twenty-one".