1221200001221 has 32 divisors (see below), whose sum is σ = 1314173548800. Its totient is φ = 1132139008000.

The previous prime is 1221200001209. The next prime is 1221200001227. The reversal of 1221200001221 is 1221000021221.

It is a cyclic number.

It is not a de Polignac number, because 1221200001221 - 2¹⁰ = 1221200000197 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221200001196 and 1221200001205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221200001227) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 55269386 + ... + 55291476.

It is an arithmetic number, because the mean of its divisors is an integer number (41067923400).

Almost surely, 2^{1221200001221} is an apocalyptic number.

It is an amenable number.

1221200001221 is a deficient number, since it is larger than the sum of its proper divisors (92973547579).

1221200001221 is a wasteful number, since it uses less digits than its factorization.

1221200001221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22717.

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

Adding to 1221200001221 its reverse (1221000021221), we get a palindrome (2442200022442).

It can be divided in two parts, 122120000 and 1221, that added together give a palindrome (122121221).

The spelling of 1221200001221 in words is "one trillion, two hundred twenty-one billion, two hundred million, one thousand, two hundred twenty-one".