121221212041243 has 4 divisors (see below), whose sum is σ = 121221241393968. Its totient is φ = 121221182688520.

The previous prime is 121221212041213. The next prime is 121221212041277. The reversal of 121221212041243 is 342140212122121.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121221212041243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121221212041213) 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 3 ways as a sum of consecutive naturals, for example, 7218343 + ... + 17162368.

It is an arithmetic number, because the mean of its divisors is an integer number (30305310348492).

Almost surely, 2^{121221212041243} is an apocalyptic number.

121221212041243 is a deficient number, since it is larger than the sum of its proper divisors (29352725).

121221212041243 is an equidigital number, since it uses as much as digits as its factorization.

121221212041243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29352724.

The product of its (nonzero) digits is 3072, while the sum is 28.

Adding to 121221212041243 its reverse (342140212122121), we get a palindrome (463361424163364).

The spelling of 121221212041243 in words is "one hundred twenty-one trillion, two hundred twenty-one billion, two hundred twelve million, forty-one thousand, two hundred forty-three".