12423821 has 6 divisors (see below), whose sum is σ = 13197930. Its totient is φ = 11692736.

The previous prime is 12423811. The next prime is 12423833. The reversal of 12423821 is 12832421.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 4778596 + 7645225 = 2186^2 + 2765^2 .

It is not a de Polignac number, because 12423821 - 2¹⁰ = 12422797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12423811) 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 5 ways as a sum of consecutive naturals, for example, 21206 + ... + 21783.

It is an arithmetic number, because the mean of its divisors is an integer number (2199655).

Almost surely, 2^12423821 is an apocalyptic number.

It is an amenable number.

12423821 is a deficient number, since it is larger than the sum of its proper divisors (774109).

12423821 is an equidigital number, since it uses as much as digits as its factorization.

12423821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43023 (or 43006 counting only the distinct ones).

The product of its digits is 768, while the sum is 23.

The square root of 12423821 is about 3524.7441041869. The cubic root of 12423821 is about 231.6070252303.

The spelling of 12423821 in words is "twelve million, four hundred twenty-three thousand, eight hundred twenty-one".