1221221021201 has 16 divisors (see below), whose sum is σ = 1267816354560. Its totient is φ = 1175489652480.

The previous prime is 1221221021173. The next prime is 1221221021219. The reversal of 1221221021201 is 1021201221221.

It is a cyclic number.

It is not a de Polignac number, because 1221221021201 - 2²² = 1221216826897 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221221021201.

It is not an unprimeable number, because it can be changed into a prime (1221221021701) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26172470 + ... + 26219088.

It is an arithmetic number, because the mean of its divisors is an integer number (79238522160).

Almost surely, 2^{1221221021201} is an apocalyptic number.

It is an amenable number.

1221221021201 is a deficient number, since it is larger than the sum of its proper divisors (46595333359).

1221221021201 is an equidigital number, since it uses as much as digits as its factorization.

1221221021201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55864.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 1221221021201 its reverse (1021201221221), we get a palindrome (2242422242422).

The spelling of 1221221021201 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-one million, twenty-one thousand, two hundred one".