1221000202221 has 16 divisors (see below), whose sum is σ = 1690398979200. Its totient is φ = 783009472448.

The previous prime is 1221000202211. The next prime is 1221000202249. The reversal of 1221000202221 is 1222020001221.

It is a cyclic number.

It is not a de Polignac number, because 1221000202221 - 2⁵ = 1221000202189 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1221000202221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221000202211) 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 15 ways as a sum of consecutive naturals, for example, 26063001 + ... + 26109806.

It is an arithmetic number, because the mean of its divisors is an integer number (105649936200).

Almost surely, 2^{1221000202221} is an apocalyptic number.

It is an amenable number.

1221000202221 is a deficient number, since it is larger than the sum of its proper divisors (469398776979).

1221000202221 is a wasteful number, since it uses less digits than its factorization.

1221000202221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52173108.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 1221000202221 its reverse (1222020001221), we get a palindrome (2443020203442).

The spelling of 1221000202221 in words is "one trillion, two hundred twenty-one billion, two hundred two thousand, two hundred twenty-one".