121122221221 has 4 divisors (see below), whose sum is σ = 122370904012. Its totient is φ = 119873538432.

The previous prime is 121122221201. The next prime is 121122221257. The reversal of 121122221221 is 122122221121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 44052132996 + 77070088225 = 209886^2 + 277615^2 .

It is a cyclic number.

It is not a de Polignac number, because 121122221221 - 2⁵ = 121122221189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121122221201) 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 3 ways as a sum of consecutive naturals, for example, 624341250 + ... + 624341443.

It is an arithmetic number, because the mean of its divisors is an integer number (30592726003).

Almost surely, 2^121122221221 is an apocalyptic number.

It is an amenable number.

121122221221 is a deficient number, since it is larger than the sum of its proper divisors (1248682791).

121122221221 is an equidigital number, since it uses as much as digits as its factorization.

121122221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1248682790.

The product of its digits is 128, while the sum is 19.

Adding to 121122221221 its reverse (122122221121), we get a palindrome (243244442342).

The spelling of 121122221221 in words is "one hundred twenty-one billion, one hundred twenty-two million, two hundred twenty-one thousand, two hundred twenty-one".