21131431348121 has 2 divisors, whose sum is σ = 21131431348122. Its totient is φ = 21131431348120.

The previous prime is 21131431348061. The next prime is 21131431348207. The reversal of 21131431348121 is 12184313413112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20513652640000 + 617778708121 = 4529200^2 + 785989^2 .

It is a cyclic number.

It is not a de Polignac number, because 21131431348121 - 2¹⁸ = 21131431085977 is a prime.

It is not a weakly prime, because it can be changed into another prime (21131431341121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10565715674060 + 10565715674061.

It is an arithmetic number, because the mean of its divisors is an integer number (10565715674061).

Almost surely, 2^{21131431348121} is an apocalyptic number.

It is an amenable number.

21131431348121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21131431348121 is an equidigital number, since it uses as much as digits as its factorization.

21131431348121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13824, while the sum is 35.

The spelling of 21131431348121 in words is "twenty-one trillion, one hundred thirty-one billion, four hundred thirty-one million, three hundred forty-eight thousand, one hundred twenty-one".