21110211211021 has 4 divisors (see below), whose sum is σ = 21110760151200. Its totient is φ = 21109662270844.

The previous prime is 21110211210923. The next prime is 21110211211057. The reversal of 21110211211021 is 12011211201112.

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 21110211211021 - 2⁹ = 21110211210509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21110211210986 and 21110211211004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21110211211091) 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, 274412401 + ... + 274489318.

It is an arithmetic number, because the mean of its divisors is an integer number (5277690037800).

Almost surely, 2^{21110211211021} is an apocalyptic number.

It is an amenable number.

21110211211021 is a deficient number, since it is larger than the sum of its proper divisors (548940179).

21110211211021 is an equidigital number, since it uses as much as digits as its factorization.

21110211211021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 548940178.

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

Adding to 21110211211021 its reverse (12011211201112), we get a palindrome (33121422412133).

Subtracting from 21110211211021 its reverse (12011211201112), we obtain a palindrome (9099000009909).

The spelling of 21110211211021 in words is "twenty-one trillion, one hundred ten billion, two hundred eleven million, two hundred eleven thousand, twenty-one".