12421661 has 4 divisors (see below), whose sum is σ = 14196192. Its totient is φ = 10647132.

The previous prime is 12421639. The next prime is 12421681. The reversal of 12421661 is 16612421.

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.

It is a cyclic number.

It is not a de Polignac number, because 12421661 - 2⁶ = 12421597 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12421601) 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 3 ways as a sum of consecutive naturals, for example, 887255 + ... + 887268.

It is an arithmetic number, because the mean of its divisors is an integer number (3549048).

Almost surely, 2^12421661 is an apocalyptic number.

It is an amenable number.

12421661 is a deficient number, since it is larger than the sum of its proper divisors (1774531).

12421661 is an equidigital number, since it uses as much as digits as its factorization.

12421661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1774530.

The product of its digits is 576, while the sum is 23.

The square root of 12421661 is about 3524.4376856458. The cubic root of 12421661 is about 231.5936020875.

The spelling of 12421661 in words is "twelve million, four hundred twenty-one thousand, six hundred sixty-one".