12643281 has 24 divisors (see below), whose sum is σ = 21088704. Its totient is φ = 7149600.

The previous prime is 12643273. The next prime is 12643283. The reversal of 12643281 is 18234621.

12643281 is a `hidden beast` number, since 12 + 643 + 2 + 8 + 1 = 666.

12643281 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 12643281 - 2³ = 12643273 is a prime.

It is a super-2 number, since 2×12643281² = 319705108889922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (12643283) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5370 + ... + 7356.

It is an arithmetic number, because the mean of its divisors is an integer number (878696).

Almost surely, 2^12643281 is an apocalyptic number.

It is an amenable number.

12643281 is a deficient number, since it is larger than the sum of its proper divisors (8445423).

12643281 is a wasteful number, since it uses less digits than its factorization.

12643281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2101 (or 2098 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 12643281 is about 3555.7391636620. The cubic root of 12643281 is about 232.9628103501.

The spelling of 12643281 in words is "twelve million, six hundred forty-three thousand, two hundred eighty-one".