12181213 has 4 divisors (see below), whose sum is σ = 13288608. Its totient is φ = 11073820.

The previous prime is 12181207. The next prime is 12181217. The reversal of 12181213 is 31218121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12181213 is a prime.

It is a Duffinian number.

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 pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 553681 + ... + 553702.

It is an arithmetic number, because the mean of its divisors is an integer number (3322152).

Almost surely, 2^12181213 is an apocalyptic number.

It is an amenable number.

12181213 is a deficient number, since it is larger than the sum of its proper divisors (1107395).

12181213 is a wasteful number, since it uses less digits than its factorization.

12181213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1107394.

The product of its digits is 96, while the sum is 19.

The square root of 12181213 is about 3490.1594519449. The cubic root of 12181213 is about 230.0895240658.

Adding to 12181213 its reverse (31218121), we get a palindrome (43399334).

The spelling of 12181213 in words is "twelve million, one hundred eighty-one thousand, two hundred thirteen".