21210111311 has 2 divisors, whose sum is σ = 21210111312. Its totient is φ = 21210111310.

The previous prime is 21210111289. The next prime is 21210111337. The reversal of 21210111311 is 11311101212.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21210111311 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21210111341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605055655 + 10605055656.

It is an arithmetic number, because the mean of its divisors is an integer number (10605055656).

Almost surely, 2^21210111311 is an apocalyptic number.

21210111311 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210111311 is an equidigital number, since it uses as much as digits as its factorization.

21210111311 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12, while the sum is 14.

Adding to 21210111311 its reverse (11311101212), we get a palindrome (32521212523).

The spelling of 21210111311 in words is "twenty-one billion, two hundred ten million, one hundred eleven thousand, three hundred eleven".