121121211201221 has 16 divisors (see below), whose sum is σ = 151008506049408. Its totient is φ = 94380012864000.

The previous prime is 121121211201181. The next prime is 121121211201229. The reversal of 121121211201221 is 122102112121121.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 121121211201221 - 2¹⁸ = 121121210939077 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 121121211201193 and 121121211201202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121121211201229) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 84388841 + ... + 85812113.

It is an arithmetic number, because the mean of its divisors is an integer number (9438031628088).

Almost surely, 2^{121121211201221} is an apocalyptic number.

121121211201221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121121211201221 is a deficient number, since it is larger than the sum of its proper divisors (29887294848187).

121121211201221 is a wasteful number, since it uses less digits than its factorization.

121121211201221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2528492.

The product of its (nonzero) digits is 64, while the sum is 20.

Adding to 121121211201221 its reverse (122102112121121), we get a palindrome (243223323322342).

The spelling of 121121211201221 in words is "one hundred twenty-one trillion, one hundred twenty-one billion, two hundred eleven million, two hundred one thousand, two hundred twenty-one".