21021131131111 has 4 divisors (see below), whose sum is σ = 21509994645832. Its totient is φ = 20532267616392.

The previous prime is 21021131131109. The next prime is 21021131131127. The reversal of 21021131131111 is 11113113112012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21021131131111 - 2¹ = 21021131131109 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021131134111) 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, 244431757296 + ... + 244431757381.

It is an arithmetic number, because the mean of its divisors is an integer number (5377498661458).

Almost surely, 2^{21021131131111} is an apocalyptic number.

21021131131111 is a deficient number, since it is larger than the sum of its proper divisors (488863514721).

21021131131111 is an equidigital number, since it uses as much as digits as its factorization.

21021131131111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 488863514720.

The product of its (nonzero) digits is 36, while the sum is 19.

Adding to 21021131131111 its reverse (11113113112012), we get a palindrome (32134244243123).

The spelling of 21021131131111 in words is "twenty-one trillion, twenty-one billion, one hundred thirty-one million, one hundred thirty-one thousand, one hundred eleven".