14128721 has 4 divisors (see below), whose sum is σ = 14151744. Its totient is φ = 14105700.

The previous prime is 14128711. The next prime is 14128733. The reversal of 14128721 is 12782141.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12782141 = 2311 ⋅5531.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-14128721 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (14128711) 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 in 3 ways as a sum of consecutive naturals, for example, 10565 + ... + 11826.

It is an arithmetic number, because the mean of its divisors is an integer number (3537936).

Almost surely, 2^14128721 is an apocalyptic number.

It is an amenable number.

14128721 is a deficient number, since it is larger than the sum of its proper divisors (23023).

14128721 is an equidigital number, since it uses as much as digits as its factorization.

14128721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23022.

The product of its digits is 896, while the sum is 26.

The square root of 14128721 is about 3758.8190964717. The cubic root of 14128721 is about 241.7506310435.

The spelling of 14128721 in words is "fourteen million, one hundred twenty-eight thousand, seven hundred twenty-one".