1221021222201 has 72 divisors (see below), whose sum is σ = 1996453560192. Its totient is φ = 718041931200.

The previous prime is 1221021222181. The next prime is 1221021222203. The reversal of 1221021222201 is 1022221201221.

It is a happy number.

1221021222201 is a `hidden beast` number, since 1 + 221 + 0 + 21 + 222 + 201 = 666.

It is not a de Polignac number, because 1221021222201 - 2¹⁸ = 1221020960057 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221021222203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 14746246 + ... + 14828816.

Almost surely, 2^{1221021222201} is an apocalyptic number.

1221021222201 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1221021222201 is a deficient number, since it is larger than the sum of its proper divisors (775432337991).

1221021222201 is a wasteful number, since it uses less digits than its factorization.

1221021222201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83003 (or 82989 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 1221021222201 its reverse (1022221201221), we get a palindrome (2243242423422).

The spelling of 1221021222201 in words is "one trillion, two hundred twenty-one billion, twenty-one million, two hundred twenty-two thousand, two hundred one".