71561780056973 has 2 divisors, whose sum is σ = 71561780056974. Its totient is φ = 71561780056972.

The previous prime is 71561780056967. The next prime is 71561780057123. The reversal of 71561780056973 is 37965008716517.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 57896470114729 + 13665309942244 = 7608973^2 + 3696662^2 .

It is a cyclic number.

It is not a de Polignac number, because 71561780056973 - 2⁶ = 71561780056909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71561780056903) 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, 35780890028486 + 35780890028487.

It is an arithmetic number, because the mean of its divisors is an integer number (35780890028487).

Almost surely, 2^{71561780056973} is an apocalyptic number.

It is an amenable number.

71561780056973 is a deficient number, since it is larger than the sum of its proper divisors (1).

71561780056973 is an equidigital number, since it uses as much as digits as its factorization.

71561780056973 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 66679200, while the sum is 65.

The spelling of 71561780056973 in words is "seventy-one trillion, five hundred sixty-one billion, seven hundred eighty million, fifty-six thousand, nine hundred seventy-three".