12011221221 has 16 divisors (see below), whose sum is σ = 16299097920. Its totient is φ = 7866288000.

The previous prime is 12011221213. The next prime is 12011221223. The reversal of 12011221221 is 12212211021.

It is not a de Polignac number, because 12011221221 - 2³ = 12011221213 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12011221221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12011221223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54286 + ... + 164223.

It is an arithmetic number, because the mean of its divisors is an integer number (1018693620).

Almost surely, 2^12011221221 is an apocalyptic number.

It is an amenable number.

12011221221 is a deficient number, since it is larger than the sum of its proper divisors (4287876699).

12011221221 is a wasteful number, since it uses less digits than its factorization.

12011221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218836.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 12011221221 its reverse (12212211021), we get a palindrome (24223432242).

The spelling of 12011221221 in words is "twelve billion, eleven million, two hundred twenty-one thousand, two hundred twenty-one".