Adding to 12640321 its reverse (12304621), we get a palindrome (24944942).
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 a Duffinian number.
Almost surely, 212640321 is an apocalyptic number.
12640321 is the 2053-rd octagonal number.
It is an amenable number.
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 square root of 12640321 is about 3555.3229107916. The cubic root of 12640321 is about 232.9446287895.
The spelling of 12640321 in words is "twelve million, six hundred forty thousand, three hundred twenty-one".