121211121221 has 8 divisors (see below), whose sum is σ = 123224189784. Its totient is φ = 119198891520.

The previous prime is 121211121203. The next prime is 121211121223. The reversal of 121211121221 is 122121112121.

It can be written as a sum of positive squares in 4 ways, for example, as 3640312225 + 117570808996 = 60335^2 + 342886^2 .

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-121211121221 is a prime.

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 121211121221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121211121223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 85085 + ... + 499661.

It is an arithmetic number, because the mean of its divisors is an integer number (15403023723).

Almost surely, 2^121211121221 is an apocalyptic number.

It is an amenable number.

121211121221 is a deficient number, since it is larger than the sum of its proper divisors (2013068563).

121211121221 is an equidigital number, since it uses as much as digits as its factorization.

121211121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 419431.

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

Adding to 121211121221 its reverse (122121112121), we get a palindrome (243332233342).

The spelling of 121211121221 in words is "one hundred twenty-one billion, two hundred eleven million, one hundred twenty-one thousand, two hundred twenty-one".