21110110012221 has 4 divisors (see below), whose sum is σ = 28146813349632. Its totient is φ = 14073406674812.

The previous prime is 21110110012219. The next prime is 21110110012253. The reversal of 21110110012221 is 12221001101112.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21110110012221 - 2¹ = 21110110012219 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21110110012221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21110110012421) 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, 3518351668701 + ... + 3518351668706.

It is an arithmetic number, because the mean of its divisors is an integer number (7036703337408).

Almost surely, 2^{21110110012221} is an apocalyptic number.

It is an amenable number.

21110110012221 is a deficient number, since it is larger than the sum of its proper divisors (7036703337411).

21110110012221 is an equidigital number, since it uses as much as digits as its factorization.

21110110012221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7036703337410.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21110110012221 its reverse (12221001101112), we get a palindrome (33331111113333).

The spelling of 21110110012221 in words is "twenty-one trillion, one hundred ten billion, one hundred ten million, twelve thousand, two hundred twenty-one".