12381720173 has 2 divisors, whose sum is σ = 12381720174. Its totient is φ = 12381720172.

The previous prime is 12381720161. The next prime is 12381720181. The reversal of 12381720173 is 37102718321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7017915529 + 5363804644 = 83773^2 + 73238^2 .

It is an emirp because it is prime and its reverse (37102718321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12381720173 - 2¹⁸ = 12381458029 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12381720473) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6190860086 + 6190860087.

It is an arithmetic number, because the mean of its divisors is an integer number (6190860087).

Almost surely, 2^12381720173 is an apocalyptic number.

It is an amenable number.

12381720173 is a deficient number, since it is larger than the sum of its proper divisors (1).

12381720173 is an equidigital number, since it uses as much as digits as its factorization.

12381720173 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14112, while the sum is 35.

The spelling of 12381720173 in words is "twelve billion, three hundred eighty-one million, seven hundred twenty thousand, one hundred seventy-three".