12761561 has 2 divisors, whose sum is σ = 12761562. Its totient is φ = 12761560.

The previous prime is 12761533. The next prime is 12761591. The reversal of 12761561 is 16516721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9803161 + 2958400 = 3131^2 + 1720^2 .

It is a cyclic number.

It is not a de Polignac number, because 12761561 - 2¹⁴ = 12745177 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (12761591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6380780 + 6380781.

It is an arithmetic number, because the mean of its divisors is an integer number (6380781).

Almost surely, 2^12761561 is an apocalyptic number.

It is an amenable number.

12761561 is a deficient number, since it is larger than the sum of its proper divisors (1).

12761561 is an equidigital number, since it uses as much as digits as its factorization.

12761561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2520, while the sum is 29.

The square root of 12761561 is about 3572.3327112686. The cubic root of 12761561 is about 233.6870252729.

The spelling of 12761561 in words is "twelve million, seven hundred sixty-one thousand, five hundred sixty-one".