21311012311 has 2 divisors, whose sum is σ = 21311012312. Its totient is φ = 21311012310.

The previous prime is 21311012309. The next prime is 21311012321. The reversal of 21311012311 is 11321011312.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21311012311 - 2¹ = 21311012309 is a prime.

Together with 21311012309, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21311012321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10655506155 + 10655506156.

It is an arithmetic number, because the mean of its divisors is an integer number (10655506156).

Almost surely, 2^21311012311 is an apocalyptic number.

21311012311 is a deficient number, since it is larger than the sum of its proper divisors (1).

21311012311 is an equidigital number, since it uses as much as digits as its factorization.

21311012311 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 16.

Adding to 21311012311 its reverse (11321011312), we get a palindrome (32632023623).

Subtracting from 21311012311 its reverse (11321011312), we obtain a palindrome (9990000999).

The spelling of 21311012311 in words is "twenty-one billion, three hundred eleven million, twelve thousand, three hundred eleven".