121210221221 has 8 divisors (see below), whose sum is σ = 128364395544. Its totient is φ = 114058731520.

The previous prime is 121210221203. The next prime is 121210221263. The reversal of 121210221221 is 122122012121.

It can be written as a sum of positive squares in 4 ways, for example, as 111032236225 + 10177984996 = 333215^2 + 100886^2 .

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-121210221221 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

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 121210221221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121210221281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 577820 + ... + 759141.

It is an arithmetic number, because the mean of its divisors is an integer number (16045549443).

Almost surely, 2^121210221221 is an apocalyptic number.

It is an amenable number.

121210221221 is a deficient number, since it is larger than the sum of its proper divisors (7154174323).

121210221221 is a wasteful number, since it uses less digits than its factorization.

121210221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1342311.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 121210221221 its reverse (122122012121), we get a palindrome (243332233342).

The spelling of 121210221221 in words is "one hundred twenty-one billion, two hundred ten million, two hundred twenty-one thousand, two hundred twenty-one".