1221121120121 has 16 divisors (see below), whose sum is σ = 1422587721600. Its totient is φ = 1026569904768.

The previous prime is 1221121120117. The next prime is 1221121120139. The reversal of 1221121120121 is 1210211211221.

It is a cyclic number.

It is not a de Polignac number, because 1221121120121 - 2² = 1221121120117 is a prime.

It is a super-2 number, since 2×1221121120121² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221121120121.

It is not an unprimeable number, because it can be changed into a prime (1221121120181) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6583586 + ... + 6766523.

It is an arithmetic number, because the mean of its divisors is an integer number (88911732600).

Almost surely, 2^{1221121120121} is an apocalyptic number.

It is an amenable number.

1221121120121 is a deficient number, since it is larger than the sum of its proper divisors (201466601479).

1221121120121 is a wasteful number, since it uses less digits than its factorization.

1221121120121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13350368.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 1221121120121 its reverse (1210211211221), we get a palindrome (2431332331342).

The spelling of 1221121120121 in words is "one trillion, two hundred twenty-one billion, one hundred twenty-one million, one hundred twenty thousand, one hundred twenty-one".