1221202112123 has 4 divisors (see below), whose sum is σ = 1395659556720. Its totient is φ = 1046744667528.

The previous prime is 1221202112063. The next prime is 1221202112159. The reversal of 1221202112123 is 3212112021221.

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

It is not a de Polignac number, because 1221202112123 - 2⁸ = 1221202111867 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221202112095 and 1221202112104.

It is not an unprimeable number, because it can be changed into a prime (1221202112623) 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, 87228722288 + ... + 87228722301.

It is an arithmetic number, because the mean of its divisors is an integer number (348914889180).

Almost surely, 2^{1221202112123} is an apocalyptic number.

1221202112123 is a deficient number, since it is larger than the sum of its proper divisors (174457444597).

1221202112123 is an equidigital number, since it uses as much as digits as its factorization.

1221202112123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174457444596.

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

Adding to 1221202112123 its reverse (3212112021221), we get a palindrome (4433314133344).

The spelling of 1221202112123 in words is "one trillion, two hundred twenty-one billion, two hundred two million, one hundred twelve thousand, one hundred twenty-three".