12721 has 2 divisors, whose sum is σ = 12722. Its totient is φ = 12720.
The previous prime is 12713. The next prime is 12739.
12721 is nontrivially palindromic in base 10.
12721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 12321 + 400 = 111^2 + 20^2 .
It is a palprime.
It is a cyclic number.
It is not a de Polignac number, because 12721 - 23 = 12713 is a prime.
It is a Chen prime.
It is an alternating number because its digits alternate between odd and even.
It is a pancake number, because a pancake can be divided into 12721 parts by 159 straight cuts.
It is a nialpdrome in base 12.
It is not a weakly prime, because it can be changed into another prime (12781) 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, 6360 + 6361.
It is an arithmetic number, because the mean of its divisors is an integer number (6361).
212721 is an apocalyptic number.
It is an amenable number.
12721 is a deficient number, since it is larger than the sum of its proper divisors (1).
12721 is an equidigital number, since it uses as much as digits as its factorization.
12721 is an odious number, because the sum of its binary digits is odd.
The product of its digits is 28, while the sum is 13.
The square root of 12721 is about 112.7874106450. The cubic root of 12721 is about 23.3439181002.
The spelling of 12721 in words is "twelve thousand, seven hundred twenty-one", and thus it is an iban number.
• e-mail: info -at- numbersaplenty.com • Privacy notice • done in 0.067 sec. • engine limits •