12640321 has 8 divisors (see below), whose sum is σ = 13014144. Its totient is φ = 12270960.

The previous prime is 12640307. The next prime is 12640351. The reversal of 12640321 is 12304621.

12640321 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12640321 - 2⁷ = 12640193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12640351) 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 in 7 ways as a sum of consecutive naturals, for example, 5131 + ... + 7183.

It is an arithmetic number, because the mean of its divisors is an integer number (1626768).

Almost surely, 2^12640321 is an apocalyptic number.

12640321 is the 2053-rd octagonal number.

It is an amenable number.

12640321 is a deficient number, since it is larger than the sum of its proper divisors (373823).

12640321 is a wasteful number, since it uses less digits than its factorization.

12640321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2231.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 12640321 is about 3555.3229107916. The cubic root of 12640321 is about 232.9446287895.

Adding to 12640321 its reverse (12304621), we get a palindrome (24944942).

The spelling of 12640321 in words is "twelve million, six hundred forty thousand, three hundred twenty-one".