12728121 has 32 divisors (see below), whose sum is σ = 20798208. Its totient is φ = 6758400.

The previous prime is 12728113. The next prime is 12728123. The reversal of 12728121 is 12182721.

12728121 = T₃₂₉ + T₃₃₀ + ... + T₄₈₁.

12728121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 12728121 - 2³ = 12728113 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 12728091 and 12728100.

It is not an unprimeable number, because it can be changed into a prime (12728123) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 35881 + ... + 36233.

It is an arithmetic number, because the mean of its divisors is an integer number (649944).

Almost surely, 2^12728121 is an apocalyptic number.

It is an amenable number.

12728121 is a deficient number, since it is larger than the sum of its proper divisors (8070087).

12728121 is a wasteful number, since it uses less digits than its factorization.

12728121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 481.

The product of its digits is 448, while the sum is 24.

The square root of 12728121 is about 3567.6492260311. The cubic root of 12728121 is about 233.4827313076.

The spelling of 12728121 in words is "twelve million, seven hundred twenty-eight thousand, one hundred twenty-one".