21311123411 has 2 divisors, whose sum is σ = 21311123412. Its totient is φ = 21311123410.

The previous prime is 21311123389. The next prime is 21311123413. The reversal of 21311123411 is 11432111312.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21311123411 is a prime.

Together with 21311123413, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21311123413) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10655561705 + 10655561706.

It is an arithmetic number, because the mean of its divisors is an integer number (10655561706).

Almost surely, 2^21311123411 is an apocalyptic number.

21311123411 is a deficient number, since it is larger than the sum of its proper divisors (1).

21311123411 is an equidigital number, since it uses as much as digits as its factorization.

21311123411 is an evil number, because the sum of its binary digits is even.

The product of its digits is 144, while the sum is 20.

Adding to 21311123411 its reverse (11432111312), we get a palindrome (32743234723).

The spelling of 21311123411 in words is "twenty-one billion, three hundred eleven million, one hundred twenty-three thousand, four hundred eleven".