12181212 has 72 divisors (see below), whose sum is σ = 32862480. Its totient is φ = 3900960.

The previous prime is 12181207. The next prime is 12181217. The reversal of 12181212 is 21218121.

It is an interprime number because it is at equal distance from previous prime (12181207) and next prime (12181217).

It is a Harshad number since it is a multiple of its sum of digits (18).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12181217) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 199662 + ... + 199722.

Almost surely, 2^12181212 is an apocalyptic number.

12181212 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12181212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16431240).

12181212 is an abundant number, since it is smaller than the sum of its proper divisors (20681268).

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

12181212 is a wasteful number, since it uses less digits than its factorization.

12181212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160 (or 109 counting only the distinct ones).

The product of its digits is 64, while the sum is 18.

The square root of 12181212 is about 3490.1593086849. The cubic root of 12181212 is about 230.0895177695.

Adding to 12181212 its reverse (21218121), we get a palindrome (33399333).

The spelling of 12181212 in words is "twelve million, one hundred eighty-one thousand, two hundred twelve".