12783821 has 4 divisors (see below), whose sum is σ = 12850944. Its totient is φ = 12716700.

The previous prime is 12783817. The next prime is 12783839. The reversal of 12783821 is 12838721.

12783821 is digitally balanced in base 3, because in such base 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.

It is a cyclic number.

It is not a de Polignac number, because 12783821 - 2² = 12783817 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 (12783851) 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, 33275 + ... + 33656.

It is an arithmetic number, because the mean of its divisors is an integer number (3212736).

Almost surely, 2^12783821 is an apocalyptic number.

It is an amenable number.

12783821 is a deficient number, since it is larger than the sum of its proper divisors (67123).

12783821 is an equidigital number, since it uses as much as digits as its factorization.

12783821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67122.

The product of its digits is 5376, while the sum is 32.

The square root of 12783821 is about 3575.4469650660. The cubic root of 12783821 is about 233.8228198298.

The spelling of 12783821 in words is "twelve million, seven hundred eighty-three thousand, eight hundred twenty-one".