12506732561 has 2 divisors, whose sum is σ = 12506732562. Its totient is φ = 12506732560.

The previous prime is 12506732549. The next prime is 12506732587. The reversal of 12506732561 is 16523760521.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10685150161 + 1821582400 = 103369^2 + 42680^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12506732561 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (12506732761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6253366280 + 6253366281.

It is an arithmetic number, because the mean of its divisors is an integer number (6253366281).

Almost surely, 2^12506732561 is an apocalyptic number.

It is an amenable number.

12506732561 is a deficient number, since it is larger than the sum of its proper divisors (1).

12506732561 is an equidigital number, since it uses as much as digits as its factorization.

12506732561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 75600, while the sum is 38.

The spelling of 12506732561 in words is "twelve billion, five hundred six million, seven hundred thirty-two thousand, five hundred sixty-one".