12131221212 has 36 divisors (see below), whose sum is σ = 33452762616. Its totient is φ = 3676127520.

The previous prime is 12131221211. The next prime is 12131221253. The reversal of 12131221212 is 21212213121.

12131221212 is a `hidden beast` number, since 121 + 312 + 21 + 212 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

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

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12131221211) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15316803 + ... + 15317594.

It is an arithmetic number, because the mean of its divisors is an integer number (929243406).

Almost surely, 2^12131221212 is an apocalyptic number.

12131221212 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

12131221212 is an abundant number, since it is smaller than the sum of its proper divisors (21321541404).

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

12131221212 is a wasteful number, since it uses less digits than its factorization.

12131221212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30634418 (or 30634413 counting only the distinct ones).

The product of its digits is 96, while the sum is 18.

Adding to 12131221212 its reverse (21212213121), we get a palindrome (33343434333).

The spelling of 12131221212 in words is "twelve billion, one hundred thirty-one million, two hundred twenty-one thousand, two hundred twelve".