12171216 has 20 divisors (see below), whose sum is σ = 31442432. Its totient is φ = 4057056.

The previous prime is 12171199. The next prime is 12171227. The reversal of 12171216 is 61217121.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 12171192 and 12171201.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 126736 + ... + 126831.

Almost surely, 2^12171216 is an apocalyptic number.

12171216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

12171216 is an abundant number, since it is smaller than the sum of its proper divisors (19271216).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12171216 is a wasteful number, since it uses less digits than its factorization.

12171216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 253578 (or 253572 counting only the distinct ones).

The product of its digits is 168, while the sum is 21.

The square root of 12171216 is about 3488.7269884587. The cubic root of 12171216 is about 230.0265627796.

Adding to 12171216 its reverse (61217121), we get a palindrome (73388337).

The spelling of 12171216 in words is "twelve million, one hundred seventy-one thousand, two hundred sixteen".