121221222121121 has 4 divisors (see below), whose sum is σ = 122024011671744. Its totient is φ = 120418432570500.

The previous prime is 121221222121033. The next prime is 121221222121159. The reversal of 121221222121121 is 121121222122121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 121221222121121 - 2¹⁸ = 121221221858977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121221222121171) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 401394775085 + ... + 401394775386.

It is an arithmetic number, because the mean of its divisors is an integer number (30506002917936).

Almost surely, 2^{121221222121121} is an apocalyptic number.

It is an amenable number.

121221222121121 is a deficient number, since it is larger than the sum of its proper divisors (802789550623).

121221222121121 is an equidigital number, since it uses as much as digits as its factorization.

121221222121121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 802789550622.

The product of its digits is 256, while the sum is 23.

Adding to 121221222121121 its reverse (121121222122121), we get a palindrome (242342444243242).

The spelling of 121221222121121 in words is "one hundred twenty-one trillion, two hundred twenty-one billion, two hundred twenty-two million, one hundred twenty-one thousand, one hundred twenty-one".