21317383432649 has 2 divisors, whose sum is σ = 21317383432650. Its totient is φ = 21317383432648.

The previous prime is 21317383432621. The next prime is 21317383432673. The reversal of 21317383432649 is 94623438371312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12661548706249 + 8655834726400 = 3558307^2 + 2942080^2 .

It is a cyclic number.

It is not a de Polignac number, because 21317383432649 - 2²⁸ = 21317114997193 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21317383432594 and 21317383432603.

It is not a weakly prime, because it can be changed into another prime (21317383432699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10658691716324 + 10658691716325.

It is an arithmetic number, because the mean of its divisors is an integer number (10658691716325).

Almost surely, 2^{21317383432649} is an apocalyptic number.

It is an amenable number.

21317383432649 is a deficient number, since it is larger than the sum of its proper divisors (1).

21317383432649 is an equidigital number, since it uses as much as digits as its factorization.

21317383432649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15676416, while the sum is 56.

The spelling of 21317383432649 in words is "twenty-one trillion, three hundred seventeen billion, three hundred eighty-three million, four hundred thirty-two thousand, six hundred forty-nine".