11111221210021 has 4 divisors (see below), whose sum is σ = 11111269044672. Its totient is φ = 11111173375372.

The previous prime is 11111221209941. The next prime is 11111221210049. The reversal of 11111221210021 is 12001212211111.

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 11111221210021 - 2²⁹ = 11110684339109 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 11111221209977 and 11111221210004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11111221210121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23567191 + ... + 24034036.

It is an arithmetic number, because the mean of its divisors is an integer number (2777817261168).

Almost surely, 2^{11111221210021} is an apocalyptic number.

It is an amenable number.

11111221210021 is a deficient number, since it is larger than the sum of its proper divisors (47834651).

11111221210021 is an equidigital number, since it uses as much as digits as its factorization.

11111221210021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47834650.

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

Adding to 11111221210021 its reverse (12001212211111), we get a palindrome (23112433421132).

The spelling of 11111221210021 in words is "eleven trillion, one hundred eleven billion, two hundred twenty-one million, two hundred ten thousand, twenty-one".