12381720529 has 2 divisors, whose sum is σ = 12381720530. Its totient is φ = 12381720528.

The previous prime is 12381720521. The next prime is 12381720539. The reversal of 12381720529 is 92502718321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12381680529 + 40000 = 111273^2 + 200^2 .

It is a cyclic number.

It is not a de Polignac number, because 12381720529 - 2³ = 12381720521 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12381720491 and 12381720500.

It is not a weakly prime, because it can be changed into another prime (12381720521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6190860264 + 6190860265.

It is an arithmetic number, because the mean of its divisors is an integer number (6190860265).

Almost surely, 2^12381720529 is an apocalyptic number.

It is an amenable number.

12381720529 is a deficient number, since it is larger than the sum of its proper divisors (1).

12381720529 is an equidigital number, since it uses as much as digits as its factorization.

12381720529 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 60480, while the sum is 40.

The spelling of 12381720529 in words is "twelve billion, three hundred eighty-one million, seven hundred twenty thousand, five hundred twenty-nine".