21311211210031 has 2 divisors, whose sum is σ = 21311211210032. Its totient is φ = 21311211210030.

The previous prime is 21311211210019. The next prime is 21311211210041. The reversal of 21311211210031 is 13001211211312.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21311211210031 is a prime.

It is a super-2 number, since 2×21311211210031² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21311211209990 and 21311211210008.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21311211210011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10655605605015 + 10655605605016.

It is an arithmetic number, because the mean of its divisors is an integer number (10655605605016).

Almost surely, 2^{21311211210031} is an apocalyptic number.

21311211210031 is a deficient number, since it is larger than the sum of its proper divisors (1).

21311211210031 is an equidigital number, since it uses as much as digits as its factorization.

21311211210031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 19.

Adding to 21311211210031 its reverse (13001211211312), we get a palindrome (34312422421343).

The spelling of 21311211210031 in words is "twenty-one trillion, three hundred eleven billion, two hundred eleven million, two hundred ten thousand, thirty-one".