1221001201221 has 8 divisors (see below), whose sum is σ = 1628018853504. Its totient is φ = 813992174880.

The previous prime is 1221001201187. The next prime is 1221001201229. The reversal of 1221001201221 is 1221021001221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1221001201221 - 2⁶ = 1221001201157 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221001201221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221001201229) 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 7 ways as a sum of consecutive naturals, for example, 1818640 + ... + 2397801.

It is an arithmetic number, because the mean of its divisors is an integer number (203502356688).

Almost surely, 2^{1221001201221} is an apocalyptic number.

It is an amenable number.

1221001201221 is a deficient number, since it is larger than the sum of its proper divisors (407017652283).

1221001201221 is an equidigital number, since it uses as much as digits as its factorization.

1221001201221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4312971.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 1221001201221 its reverse (1221021001221), we get a palindrome (2442022202442).

The spelling of 1221001201221 in words is "one trillion, two hundred twenty-one billion, one million, two hundred one thousand, two hundred twenty-one".