21112220110021 has 4 divisors (see below), whose sum is σ = 21121632604512. Its totient is φ = 21102807615532.

The previous prime is 21112220110019. The next prime is 21112220110039. The reversal of 21112220110021 is 12001102221112.

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 21112220110021 - 2¹ = 21112220110019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21112220109977 and 21112220110004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21112220110321) 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, 4706243881 + ... + 4706248366.

It is an arithmetic number, because the mean of its divisors is an integer number (5280408151128).

Almost surely, 2^{21112220110021} is an apocalyptic number.

It is an amenable number.

21112220110021 is a deficient number, since it is larger than the sum of its proper divisors (9412494491).

21112220110021 is an equidigital number, since it uses as much as digits as its factorization.

21112220110021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9412494490.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21112220110021 its reverse (12001102221112), we get a palindrome (33113322331133).

The spelling of 21112220110021 in words is "twenty-one trillion, one hundred twelve billion, two hundred twenty million, one hundred ten thousand, twenty-one".