12420321 has 4 divisors (see below), whose sum is σ = 16560432. Its totient is φ = 8280212.

The previous prime is 12420313. The next prime is 12420329. The reversal of 12420321 is 12302421.

12420321 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12302421 = 3 ⋅4100807.

It is an interprime number because it is at equal distance from previous prime (12420313) and next prime (12420329).

It is a cyclic number.

It is not a de Polignac number, because 12420321 - 2³ = 12420313 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 12420321.

It is not an unprimeable number, because it can be changed into a prime (12420329) 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, 2070051 + ... + 2070056.

It is an arithmetic number, because the mean of its divisors is an integer number (4140108).

Almost surely, 2^12420321 is an apocalyptic number.

It is an amenable number.

12420321 is a deficient number, since it is larger than the sum of its proper divisors (4140111).

12420321 is an equidigital number, since it uses as much as digits as its factorization.

12420321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4140110.

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 12420321 is about 3524.2475792714. The cubic root of 12420321 is about 231.5852739853.

Adding to 12420321 its reverse (12302421), we get a palindrome (24722742).

The spelling of 12420321 in words is "twelve million, four hundred twenty thousand, three hundred twenty-one".