1221243220323 has 48 divisors (see below), whose sum is σ = 2073362636800. Its totient is φ = 692358138864.

The previous prime is 1221243220243. The next prime is 1221243220343. The reversal of 1221243220323 is 3230223421221.

1221243220323 is a `hidden beast` number, since 1 + 2 + 2 + 1 + 2 + 432 + 203 + 23 = 666.

It is not a de Polignac number, because 1221243220323 - 2¹² = 1221243216227 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221243220343) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1165465 + ... + 1949562.

Almost surely, 2^{1221243220323} is an apocalyptic number.

1221243220323 is a deficient number, since it is larger than the sum of its proper divisors (852119416477).

1221243220323 is a wasteful number, since it uses less digits than its factorization.

1221243220323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3115181 (or 3115164 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 27.

Adding to 1221243220323 its reverse (3230223421221), we get a palindrome (4451466641544).

The spelling of 1221243220323 in words is "one trillion, two hundred twenty-one billion, two hundred forty-three million, two hundred twenty thousand, three hundred twenty-three".