121123212221 has 16 divisors (see below), whose sum is σ = 132374736000. Its totient is φ = 109911916800.

The previous prime is 121123212209. The next prime is 121123212253. The reversal of 121123212221 is 122212321121.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121123212221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121123212193 and 121123212202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121128212221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22431680 + ... + 22437078.

It is an arithmetic number, because the mean of its divisors is an integer number (8273421000).

Almost surely, 2^121123212221 is an apocalyptic number.

121123212221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121123212221 is a deficient number, since it is larger than the sum of its proper divisors (11251523779).

121123212221 is a wasteful number, since it uses less digits than its factorization.

121123212221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8740.

The product of its digits is 192, while the sum is 20.

Adding to 121123212221 its reverse (122212321121), we get a palindrome (243335533342).

The spelling of 121123212221 in words is "one hundred twenty-one billion, one hundred twenty-three million, two hundred twelve thousand, two hundred twenty-one".