12921 has 8 divisors (see below), whose sum is σ = 17760. Its totient is φ = 8352.

The previous prime is 12919. The next prime is 12923.

It is a happy number.

12921 is nontrivially palindromic in base 10.

It is an interprime number because it is at equal distance from previous prime (12919) and next prime (12923).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 12921 - 2¹ = 12919 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a plaindrome in base 14.

It is a self number, because there is not a number n which added to its sum of digits gives 12921.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 12921.

It is not an unprimeable number, because it can be changed into a prime (12923) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 141 + ... + 213.

It is an arithmetic number, because the mean of its divisors is an integer number (2220).

2¹²⁹²¹ is an apocalyptic number.

It is an amenable number.

12921 is a deficient number, since it is larger than the sum of its proper divisors (4839).

12921 is an equidigital number, since it uses as much as digits as its factorization.

12921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135.

The product of its digits is 36, while the sum is 15.

The square root of 12921 is about 113.6705766678. The cubic root of 12921 is about 23.4656204696.

The spelling of 12921 in words is "twelve thousand, nine hundred twenty-one".