12745721 has 2 divisors, whose sum is σ = 12745722. Its totient is φ = 12745720.

The previous prime is 12745717. The next prime is 12745739. The reversal of 12745721 is 12754721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11155600 + 1590121 = 3340^2 + 1261^2 .

It is a cyclic number.

It is not a de Polignac number, because 12745721 - 2² = 12745717 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (12745021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6372860 + 6372861.

It is an arithmetic number, because the mean of its divisors is an integer number (6372861).

Almost surely, 2^12745721 is an apocalyptic number.

It is an amenable number.

12745721 is a deficient number, since it is larger than the sum of its proper divisors (1).

12745721 is an equidigital number, since it uses as much as digits as its factorization.

12745721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3920, while the sum is 29.

The square root of 12745721 is about 3570.1149841427. The cubic root of 12745721 is about 233.5902989908.

The spelling of 12745721 in words is "twelve million, seven hundred forty-five thousand, seven hundred twenty-one".