1212000021221 has 6 divisors (see below), whose sum is σ = 1332198370566. Its totient is φ = 1101818201000.

The previous prime is 1212000021217. The next prime is 1212000021223. The reversal of 1212000021221 is 1221200002121.

It can be written as a sum of positive squares in only one way, i.e., 713203896196 + 498796125025 = 844514^2 + 706255^2 .

It is not a de Polignac number, because 1212000021221 - 2² = 1212000021217 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1212000021196 and 1212000021205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212000021223) 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 5 ways as a sum of consecutive naturals, for example, 5008264430 + ... + 5008264671.

It is an arithmetic number, because the mean of its divisors is an integer number (222033061761).

Almost surely, 2^{1212000021221} is an apocalyptic number.

1212000021221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1212000021221 is a deficient number, since it is larger than the sum of its proper divisors (120198349345).

1212000021221 is a wasteful number, since it uses less digits than its factorization.

1212000021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10016529123 (or 10016529112 counting only the distinct ones).

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

Adding to 1212000021221 its reverse (1221200002121), we get a palindrome (2433200023342).

The spelling of 1212000021221 in words is "one trillion, two hundred twelve billion, twenty-one thousand, two hundred twenty-one".