1212212101221 has 24 divisors (see below), whose sum is σ = 1914915936960. Its totient is φ = 732841872000.

The previous prime is 1212212101193. The next prime is 1212212101229. The reversal of 1212212101221 is 1221012122121.

1212212101221 is a `hidden beast` number, since 1 + 212 + 21 + 210 + 1 + 221 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-1212212101221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1212212101194 and 1212212101203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212212101229) 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 23 ways as a sum of consecutive naturals, for example, 15227841 + ... + 15307238.

It is an arithmetic number, because the mean of its divisors is an integer number (79788164040).

Almost surely, 2^{1212212101221} is an apocalyptic number.

1212212101221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1212212101221 is a deficient number, since it is larger than the sum of its proper divisors (702703835739).

1212212101221 is a wasteful number, since it uses less digits than its factorization.

1212212101221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30535497 (or 30535494 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 1212212101221 its reverse (1221012122121), we get a palindrome (2433224223342).

The spelling of 1212212101221 in words is "one trillion, two hundred twelve billion, two hundred twelve million, one hundred one thousand, two hundred twenty-one".