12216071 has 4 divisors (see below), whose sum is σ = 13961232. Its totient is φ = 10470912.

The previous prime is 12216041. The next prime is 12216079. The reversal of 12216071 is 17061221.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12216071 is a prime.

It is a Duffinian number.

It is a plaindrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12216079) 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 3 ways as a sum of consecutive naturals, for example, 872570 + ... + 872583.

It is an arithmetic number, because the mean of its divisors is an integer number (3490308).

Almost surely, 2^12216071 is an apocalyptic number.

12216071 is a deficient number, since it is larger than the sum of its proper divisors (1745161).

12216071 is an equidigital number, since it uses as much as digits as its factorization.

12216071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1745160.

The product of its (nonzero) digits is 168, while the sum is 20.

The square root of 12216071 is about 3495.1496391428. The cubic root of 12216071 is about 230.3087912894.

Adding to 12216071 its reverse (17061221), we get a palindrome (29277292).

The spelling of 12216071 in words is "twelve million, two hundred sixteen thousand, seventy-one".