12216771 has 32 divisors (see below), whose sum is σ = 21255680. Its totient is φ = 6788448.

The previous prime is 12216767. The next prime is 12216781. The reversal of 12216771 is 17761221.

It is not a de Polignac number, because 12216771 - 2² = 12216767 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12216731) 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 31 ways as a sum of consecutive naturals, for example, 6120 + ... + 7866.

It is an arithmetic number, because the mean of its divisors is an integer number (664240).

Almost surely, 2^12216771 is an apocalyptic number.

12216771 is a deficient number, since it is larger than the sum of its proper divisors (9038909).

12216771 is a wasteful number, since it uses less digits than its factorization.

12216771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1800 (or 1794 counting only the distinct ones).

The product of its digits is 1176, while the sum is 27.

The square root of 12216771 is about 3495.2497764824. The cubic root of 12216771 is about 230.3131902236.

Adding to 12216771 its reverse (17761221), we get a palindrome (29977992).

The spelling of 12216771 in words is "twelve million, two hundred sixteen thousand, seven hundred seventy-one".