1221203221121 has 8 divisors (see below), whose sum is σ = 1315151187840. Its totient is φ = 1127256576912.

The previous prime is 1221203221111. The next prime is 1221203221127. The reversal of 1221203221121 is 1211223021221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221203221121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221203221093 and 1221203221102.

It is not an unprimeable number, because it can be changed into a prime (1221203221127) 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 7 ways as a sum of consecutive naturals, for example, 2459006 + ... + 2913608.

It is an arithmetic number, because the mean of its divisors is an integer number (164393898480).

Almost surely, 2^{1221203221121} is an apocalyptic number.

It is an amenable number.

1221203221121 is a deficient number, since it is larger than the sum of its proper divisors (93947966719).

1221203221121 is a wasteful number, since it uses less digits than its factorization.

1221203221121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 661255.

The product of its (nonzero) digits is 192, while the sum is 20.

Adding to 1221203221121 its reverse (1211223021221), we get a palindrome (2432426242342).

The spelling of 1221203221121 in words is "one trillion, two hundred twenty-one billion, two hundred three million, two hundred twenty-one thousand, one hundred twenty-one".