12665945 has 4 divisors (see below), whose sum is σ = 15199140. Its totient is φ = 10132752.

The previous prime is 12665941. The next prime is 12665957. The reversal of 12665945 is 54956621.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54956621 = 191 ⋅287731.

It can be written as a sum of positive squares in 2 ways, for example, as 2374681 + 10291264 = 1541^2 + 3208^2 .

It is a cyclic number.

It is not a de Polignac number, because 12665945 - 2² = 12665941 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12665899 and 12665908.

It is not an unprimeable number, because it can be changed into a prime (12665941) 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, 1266590 + ... + 1266599.

It is an arithmetic number, because the mean of its divisors is an integer number (3799785).

Almost surely, 2^12665945 is an apocalyptic number.

It is an amenable number.

12665945 is a deficient number, since it is larger than the sum of its proper divisors (2533195).

12665945 is an equidigital number, since it uses as much as digits as its factorization.

12665945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2533194.

The product of its digits is 64800, while the sum is 38.

The square root of 12665945 is about 3558.9246971522. The cubic root of 12665945 is about 233.1019281793.

The spelling of 12665945 in words is "twelve million, six hundred sixty-five thousand, nine hundred forty-five".