121221222222221 has 8 divisors (see below), whose sum is σ = 133250809161888. Its totient is φ = 109359881254000.

The previous prime is 121221222222211. The next prime is 121221222222227. The reversal of 121221222222221 is 122222222122121.

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 121221222222221 - 2¹⁸ = 121221221960077 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121221222222227) 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, 42061491350 + ... + 42061494231.

It is an arithmetic number, because the mean of its divisors is an integer number (16656351145236).

Almost surely, 2^{121221222222221} is an apocalyptic number.

121221222222221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121221222222221 is a deficient number, since it is larger than the sum of its proper divisors (12029586939667).

121221222222221 is a wasteful number, since it uses less digits than its factorization.

121221222222221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84122985723.

The product of its digits is 2048, while the sum is 26.

Adding to 121221222222221 its reverse (122222222122121), we get a palindrome (243443444344342).

The spelling of 121221222222221 in words is "one hundred twenty-one trillion, two hundred twenty-one billion, two hundred twenty-two million, two hundred twenty-two thousand, two hundred twenty-one".