12405665 has 8 divisors (see below), whose sum is σ = 15762600. Its totient is φ = 9340672.

The previous prime is 12405661. The next prime is 12405667. The reversal of 12405665 is 56650421.

It can be written as a sum of positive squares in 4 ways, for example, as 6990736 + 5414929 = 2644^2 + 2327^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12405665 - 2² = 12405661 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12405661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 72890 + ... + 73059.

It is an arithmetic number, because the mean of its divisors is an integer number (1970325).

Almost surely, 2^12405665 is an apocalyptic number.

It is an amenable number.

12405665 is a deficient number, since it is larger than the sum of its proper divisors (3356935).

12405665 is a wasteful number, since it uses less digits than its factorization.

12405665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145971.

The product of its (nonzero) digits is 7200, while the sum is 29.

The square root of 12405665 is about 3522.1676564298. The cubic root of 12405665 is about 231.4941477932.

The spelling of 12405665 in words is "twelve million, four hundred five thousand, six hundred sixty-five".