12216881 has 4 divisors (see below), whose sum is σ = 12248052. Its totient is φ = 12185712.

The previous prime is 12216877. The next prime is 12216901. The reversal of 12216881 is 18861221.

12216881 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.

It can be written as a sum of positive squares in 2 ways, for example, as 4326400 + 7890481 = 2080^2 + 2809^2 .

It is a cyclic number.

It is not a de Polignac number, because 12216881 - 2² = 12216877 is a prime.

It is a super-2 number, since 2×12216881² = 298504362736322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12216181) 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, 14990 + ... + 15783.

It is an arithmetic number, because the mean of its divisors is an integer number (3062013).

Almost surely, 2^12216881 is an apocalyptic number.

It is an amenable number.

12216881 is a deficient number, since it is larger than the sum of its proper divisors (31171).

12216881 is an equidigital number, since it uses as much as digits as its factorization.

12216881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31170.

The product of its digits is 1536, while the sum is 29.

The square root of 12216881 is about 3495.2655120892. The cubic root of 12216881 is about 230.3138814694.

The spelling of 12216881 in words is "twelve million, two hundred sixteen thousand, eight hundred eighty-one".