12718721 has 2 divisors, whose sum is σ = 12718722. Its totient is φ = 12718720.

The previous prime is 12718709. The next prime is 12718757. The reversal of 12718721 is 12781721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9388096 + 3330625 = 3064^2 + 1825^2 .

It is a cyclic number.

It is not a de Polignac number, because 12718721 - 2¹⁰ = 12717697 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (12718621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6359360 + 6359361.

It is an arithmetic number, because the mean of its divisors is an integer number (6359361).

Almost surely, 2^12718721 is an apocalyptic number.

It is an amenable number.

12718721 is a deficient number, since it is larger than the sum of its proper divisors (1).

12718721 is an equidigital number, since it uses as much as digits as its factorization.

12718721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1568, while the sum is 29.

The square root of 12718721 is about 3566.3315886216. The cubic root of 12718721 is about 233.4252397584.

The spelling of 12718721 in words is "twelve million, seven hundred eighteen thousand, seven hundred twenty-one".