12643261 has 4 divisors (see below), whose sum is σ = 13192992. Its totient is φ = 12093532.

The previous prime is 12643249. The next prime is 12643273. The reversal of 12643261 is 16234621.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (12643249) and next prime (12643273).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12643261 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12643201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 274831 + ... + 274876.

It is an arithmetic number, because the mean of its divisors is an integer number (3298248).

Almost surely, 2^12643261 is an apocalyptic number.

It is an amenable number.

12643261 is a deficient number, since it is larger than the sum of its proper divisors (549731).

12643261 is an equidigital number, since it uses as much as digits as its factorization.

12643261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 549730.

The product of its digits is 1728, while the sum is 25.

The square root of 12643261 is about 3555.7363513062. The cubic root of 12643261 is about 232.9626875112.

Adding to 12643261 its reverse (16234621), we get a palindrome (28877882).

The spelling of 12643261 in words is "twelve million, six hundred forty-three thousand, two hundred sixty-one".