121121212122221 has 8 divisors (see below), whose sum is σ = 121191652850688. Its totient is φ = 121050790182000.

The previous prime is 121121212122191. The next prime is 121121212122223. The reversal of 121121212122221 is 122221212121121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 121121212122221 - 2²⁶ = 121121145013357 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 (121121212122223) 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, 8210291 + ... + 17596911.

It is an arithmetic number, because the mean of its divisors is an integer number (15148956606336).

Almost surely, 2^{121121212122221} is an apocalyptic number.

It is an amenable number.

121121212122221 is a deficient number, since it is larger than the sum of its proper divisors (70440728467).

121121212122221 is an equidigital number, since it uses as much as digits as its factorization.

121121212122221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9394123.

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

Adding to 121121212122221 its reverse (122221212121121), we get a palindrome (243342424243342).

The spelling of 121121212122221 in words is "one hundred twenty-one trillion, one hundred twenty-one billion, two hundred twelve million, one hundred twenty-two thousand, two hundred twenty-one".