12643240 has 32 divisors (see below), whose sum is σ = 30122280. Its totient is φ = 4759552.

The previous prime is 12643201. The next prime is 12643249. The reversal of 12643240 is 4234621.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 11710084 + 933156 = 3422^2 + 966^2 .

It is not an unprimeable number, because it can be changed into a prime (12643249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8617 + ... + 9976.

Almost surely, 2^12643240 is an apocalyptic number.

12643240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12643240 is an abundant number, since it is smaller than the sum of its proper divisors (17479040).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12643240 is a wasteful number, since it uses less digits than its factorization.

12643240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18621 (or 18617 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 12643240 is about 3555.7333983301. The cubic root of 12643240 is about 232.9625585303.

Adding to 12643240 its reverse (4234621), we get a palindrome (16877861).

The spelling of 12643240 in words is "twelve million, six hundred forty-three thousand, two hundred forty".