1221201120001 has 4 divisors (see below), whose sum is σ = 1221209766100. Its totient is φ = 1221192473904.

The previous prime is 1221201119939. The next prime is 1221201120037. The reversal of 1221201120001 is 1000211021221.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1102468500225 + 118732619776 = 1049985^2 + 344576^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221201120001 - 2¹¹ = 1221201117953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221201120101) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4107606 + ... + 4394863.

It is an arithmetic number, because the mean of its divisors is an integer number (305302441525).

Almost surely, 2^{1221201120001} is an apocalyptic number.

It is an amenable number.

1221201120001 is a deficient number, since it is larger than the sum of its proper divisors (8646099).

1221201120001 is an equidigital number, since it uses as much as digits as its factorization.

1221201120001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8646098.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 1221201120001 its reverse (1000211021221), we get a palindrome (2221412141222).

The spelling of 1221201120001 in words is "one trillion, two hundred twenty-one billion, two hundred one million, one hundred twenty thousand, one".