1221221221984 has 48 divisors (see below), whose sum is σ = 2418562985328. Its totient is φ = 606984136192.

The previous prime is 1221221221967. The next prime is 1221221221991. The reversal of 1221221221984 is 4891221221221.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 45088254 + ... + 45115330.

It is an arithmetic number, because the mean of its divisors is an integer number (50386728861).

Almost surely, 2^{1221221221984} is an apocalyptic number.

It is an amenable number.

1221221221984 is a deficient number, since it is larger than the sum of its proper divisors (1197341763344).

1221221221984 is a wasteful number, since it uses less digits than its factorization.

1221221221984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35407 (or 35399 counting only the distinct ones).

The product of its digits is 18432, while the sum is 37.

The spelling of 1221221221984 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-one million, two hundred twenty-one thousand, nine hundred eighty-four".