121221221211211 has 4 divisors (see below), whose sum is σ = 132241332230424. Its totient is φ = 110201110192000.

The previous prime is 121221221211203. The next prime is 121221221211253. The reversal of 121221221211211 is 112112122122121.

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

It is a cyclic number.

It is not a de Polignac number, because 121221221211211 - 2³ = 121221221211203 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121221221251211) 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, 5510055509590 + ... + 5510055509611.

It is an arithmetic number, because the mean of its divisors is an integer number (33060333057606).

Almost surely, 2^{121221221211211} is an apocalyptic number.

121221221211211 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

121221221211211 is a deficient number, since it is larger than the sum of its proper divisors (11020111019213).

121221221211211 is a wasteful number, since it uses less digits than its factorization.

121221221211211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11020111019212.

The product of its digits is 128, while the sum is 22.

Adding to 121221221211211 its reverse (112112122122121), we get a palindrome (233333343333332).

The spelling of 121221221211211 in words is "one hundred twenty-one trillion, two hundred twenty-one billion, two hundred twenty-one million, two hundred eleven thousand, two hundred eleven".