12420665 has 4 divisors (see below), whose sum is σ = 14904804. Its totient is φ = 9936528.

The previous prime is 12420649. The next prime is 12420673. The reversal of 12420665 is 56602421.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56602421 = 383 ⋅147787.

It can be written as a sum of positive squares in 2 ways, for example, as 3396649 + 9024016 = 1843^2 + 3004^2 .

It is a cyclic number.

It is not a de Polignac number, because 12420665 - 2⁴ = 12420649 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 1242062 + ... + 1242071.

It is an arithmetic number, because the mean of its divisors is an integer number (3726201).

Almost surely, 2^12420665 is an apocalyptic number.

It is an amenable number.

12420665 is a deficient number, since it is larger than the sum of its proper divisors (2484139).

12420665 is an equidigital number, since it uses as much as digits as its factorization.

12420665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2484138.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 12420665 is about 3524.2963836772. The cubic root of 12420665 is about 231.5874120030.

The spelling of 12420665 in words is "twelve million, four hundred twenty thousand, six hundred sixty-five".