1221012121103 has 4 divisors (see below), whose sum is σ = 1239236182680. Its totient is φ = 1202788059528.

The previous prime is 1221012121079. The next prime is 1221012121159. The reversal of 1221012121103 is 3011212101221.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 1221012121103 - 2⁶ = 1221012121039 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 (1221012124103) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9112030688 + ... + 9112030821.

It is an arithmetic number, because the mean of its divisors is an integer number (309809045670).

Almost surely, 2^{1221012121103} is an apocalyptic number.

1221012121103 is a deficient number, since it is larger than the sum of its proper divisors (18224061577).

1221012121103 is an equidigital number, since it uses as much as digits as its factorization.

1221012121103 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18224061576.

The product of its (nonzero) digits is 48, while the sum is 17.

Adding to 1221012121103 its reverse (3011212101221), we get a palindrome (4232224222324).

The spelling of 1221012121103 in words is "one trillion, two hundred twenty-one billion, twelve million, one hundred twenty-one thousand, one hundred three".