1221221211201 has 6 divisors (see below), whose sum is σ = 1763986193970. Its totient is φ = 814147474128.

The previous prime is 1221221211167. The next prime is 1221221211211. The reversal of 1221221211201 is 1021121221221.

1221221211201 is a `hidden beast` number, since 1 + 221 + 221 + 21 + 1 + 201 = 666.

It can be written as a sum of positive squares in only one way, i.e., 937409303601 + 283811907600 = 968199^2 + 532740^2 .

It is not a de Polignac number, because 1221221211201 - 2⁶ = 1221221211137 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221221211211) 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 5 ways as a sum of consecutive naturals, for example, 67845622836 + ... + 67845622853.

It is an arithmetic number, because the mean of its divisors is an integer number (293997698995).

Almost surely, 2^{1221221211201} is an apocalyptic number.

It is an amenable number.

1221221211201 is a deficient number, since it is larger than the sum of its proper divisors (542764982769).

1221221211201 is a wasteful number, since it uses less digits than its factorization.

1221221211201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135691245695 (or 135691245692 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 1221221211201 its reverse (1021121221221), we get a palindrome (2242342432422).

The spelling of 1221221211201 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-one million, two hundred eleven thousand, two hundred one".