1323121110221 has 4 divisors (see below), whose sum is σ = 1323163128252. Its totient is φ = 1323079092192.

The previous prime is 1323121110217. The next prime is 1323121110277. The reversal of 1323121110221 is 1220111213231.

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

It can be written as a sum of positive squares in 2 ways, for example, as 272473560100 + 1050647550121 = 521990^2 + 1025011^2 .

It is a cyclic number.

It is not a de Polignac number, because 1323121110221 - 2² = 1323121110217 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1323121110193 and 1323121110202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1323111110221) 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, 20961746 + ... + 21024771.

It is an arithmetic number, because the mean of its divisors is an integer number (330790782063).

Almost surely, 2^{1323121110221} is an apocalyptic number.

It is an amenable number.

1323121110221 is a deficient number, since it is larger than the sum of its proper divisors (42018031).

1323121110221 is an equidigital number, since it uses as much as digits as its factorization.

1323121110221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42018030.

The product of its (nonzero) digits is 144, while the sum is 20.

Adding to 1323121110221 its reverse (1220111213231), we get a palindrome (2543232323452).

The spelling of 1323121110221 in words is "one trillion, three hundred twenty-three billion, one hundred twenty-one million, one hundred ten thousand, two hundred twenty-one".