12102021221 has 2 divisors, whose sum is σ = 12102021222. Its totient is φ = 12102021220.

The previous prime is 12102021199. The next prime is 12102021241. The reversal of 12102021221 is 12212020121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8087404900 + 4014616321 = 89930^2 + 63361^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12102021221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12102021196 and 12102021205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12102021241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6051010610 + 6051010611.

It is an arithmetic number, because the mean of its divisors is an integer number (6051010611).

Almost surely, 2^12102021221 is an apocalyptic number.

It is an amenable number.

12102021221 is a deficient number, since it is larger than the sum of its proper divisors (1).

12102021221 is an equidigital number, since it uses as much as digits as its factorization.

12102021221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 12102021221 its reverse (12212020121), we get a palindrome (24314041342).

It can be divided in two parts, 121020 and 21221, that added together give a palindrome (142241).

The spelling of 12102021221 in words is "twelve billion, one hundred two million, twenty-one thousand, two hundred twenty-one".