12908821 has 4 divisors (see below), whose sum is σ = 12920032. Its totient is φ = 12897612.

The previous prime is 12908807. The next prime is 12908849. The reversal of 12908821 is 12880921.

It is a happy number.

12908821 is digitally balanced in base 2, 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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12908821 is a prime.

It is a super-2 number, since 2×12908821² = 333275319220082, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12908851) 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, 3651 + ... + 6256.

It is an arithmetic number, because the mean of its divisors is an integer number (3230008).

Almost surely, 2^12908821 is an apocalyptic number.

It is an amenable number.

12908821 is a deficient number, since it is larger than the sum of its proper divisors (11211).

12908821 is an equidigital number, since it uses as much as digits as its factorization.

12908821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11210.

The product of its (nonzero) digits is 2304, while the sum is 31.

The square root of 12908821 is about 3592.8847741056. The cubic root of 12908821 is about 234.5824545655.

The spelling of 12908821 in words is "twelve million, nine hundred eight thousand, eight hundred twenty-one".