12919561 has 2 divisors, whose sum is σ = 12919562. Its totient is φ = 12919560.

The previous prime is 12919559. The next prime is 12919567. The reversal of 12919561 is 16591921.

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., 11431161 + 1488400 = 3381^2 + 1220^2 .

It is a cyclic number.

It is not a de Polignac number, because 12919561 - 2¹ = 12919559 is a prime.

Together with 12919559, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (12919567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6459780 + 6459781.

It is an arithmetic number, because the mean of its divisors is an integer number (6459781).

Almost surely, 2^12919561 is an apocalyptic number.

It is an amenable number.

12919561 is a deficient number, since it is larger than the sum of its proper divisors (1).

12919561 is an equidigital number, since it uses as much as digits as its factorization.

12919561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4860, while the sum is 34.

The square root of 12919561 is about 3594.3790840700. The cubic root of 12919561 is about 234.6474932233.

The spelling of 12919561 in words is "twelve million, nine hundred nineteen thousand, five hundred sixty-one".