Adding to 1212221131 its reverse (1311222121), we get a palindrome (2523443252).
It is a semiprime because it is the product of two primes.
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-1212221131 is a prime.
It is a Duffinian number.
Almost surely, 21212221131 is an apocalyptic number.
1212221131 is a gapful number since it is divisible by the number (11) formed by its first and last digit.
1212221131 is a wasteful number, since it uses less digits than its factorization.
1212221131 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 110201932.
The square root of 1212221131 is about 34816.9661372153. The cubic root of 1212221131 is about 1066.2538608463.
The spelling of 1212221131 in words is "one billion, two hundred twelve million, two hundred twenty-one thousand, one hundred thirty-one".