1212001220221 has 16 divisors (see below), whose sum is σ = 1389595092480. Its totient is φ = 1046331958320.

The previous prime is 1212001220201. The next prime is 1212001220237. The reversal of 1212001220221 is 1220221002121.

It is a happy number.

It is not a de Polignac number, because 1212001220221 - 2⁵ = 1212001220189 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1212001220195 and 1212001220204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212001220201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17196915 + ... + 17267248.

It is an arithmetic number, because the mean of its divisors is an integer number (86849693280).

Almost surely, 2^{1212001220221} is an apocalyptic number.

1212001220221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1212001220221 is a deficient number, since it is larger than the sum of its proper divisors (177593872259).

1212001220221 is a wasteful number, since it uses less digits than its factorization.

1212001220221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34464336.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 1212001220221 its reverse (1220221002121), we get a palindrome (2432222222342).

The spelling of 1212001220221 in words is "one trillion, two hundred twelve billion, one million, two hundred twenty thousand, two hundred twenty-one".