21131431341121 has 2 divisors, whose sum is σ = 21131431341122. Its totient is φ = 21131431341120.

The previous prime is 21131431341103. The next prime is 21131431341133. The reversal of 21131431341121 is 12114313413112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13713979091121 + 7417452250000 = 3703239^2 + 2723500^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21131431341121 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21131431341121.

It is not a weakly prime, because it can be changed into another prime (21131431348121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10565715670560 + 10565715670561.

It is an arithmetic number, because the mean of its divisors is an integer number (10565715670561).

Almost surely, 2^{21131431341121} is an apocalyptic number.

It is an amenable number.

21131431341121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21131431341121 is an equidigital number, since it uses as much as digits as its factorization.

21131431341121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1728, while the sum is 28.

Adding to 21131431341121 its reverse (12114313413112), we get a palindrome (33245744754233).

The spelling of 21131431341121 in words is "twenty-one trillion, one hundred thirty-one billion, four hundred thirty-one million, three hundred forty-one thousand, one hundred twenty-one".