20431534323217 has 2 divisors, whose sum is σ = 20431534323218. Its totient is φ = 20431534323216.

The previous prime is 20431534323133. The next prime is 20431534323223. The reversal of 20431534323217 is 71232343513402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15828947630721 + 4602586692496 = 3978561^2 + 2145364^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20431534323217 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20431534323217.

It is not a weakly prime, because it can be changed into another prime (20431534423217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10215767161608 + 10215767161609.

It is an arithmetic number, because the mean of its divisors is an integer number (10215767161609).

Almost surely, 2^{20431534323217} is an apocalyptic number.

It is an amenable number.

20431534323217 is a deficient number, since it is larger than the sum of its proper divisors (1).

20431534323217 is an equidigital number, since it uses as much as digits as its factorization.

20431534323217 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 362880, while the sum is 40.

Adding to 20431534323217 its reverse (71232343513402), we get a palindrome (91663877836619).

The spelling of 20431534323217 in words is "twenty trillion, four hundred thirty-one billion, five hundred thirty-four million, three hundred twenty-three thousand, two hundred seventeen".