12638765 has 4 divisors (see below), whose sum is σ = 15166524. Its totient is φ = 10111008.

The previous prime is 12638761. The next prime is 12638767. The reversal of 12638765 is 56783621.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3433609 + 9205156 = 1853^2 + 3034^2 .

It is a cyclic number.

It is not a de Polignac number, because 12638765 - 2² = 12638761 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 (12638761) 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 3 ways as a sum of consecutive naturals, for example, 1263872 + ... + 1263881.

It is an arithmetic number, because the mean of its divisors is an integer number (3791631).

Almost surely, 2^12638765 is an apocalyptic number.

It is an amenable number.

12638765 is a deficient number, since it is larger than the sum of its proper divisors (2527759).

12638765 is an equidigital number, since it uses as much as digits as its factorization.

12638765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2527758.

The product of its digits is 60480, while the sum is 38.

The square root of 12638765 is about 3555.1040772388. The cubic root of 12638765 is about 232.9350700471.

The spelling of 12638765 in words is "twelve million, six hundred thirty-eight thousand, seven hundred sixty-five".