1221311203103 has 4 divisors (see below), whose sum is σ = 1222231559520. Its totient is φ = 1220390846688.

The previous prime is 1221311203067. The next prime is 1221311203121. The reversal of 1221311203103 is 3013021131221.

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 1221311203103 - 2¹⁸ = 1221310940959 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 (1221311203153) 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, 460176218 + ... + 460178871.

It is an arithmetic number, because the mean of its divisors is an integer number (305557889880).

Almost surely, 2^{1221311203103} is an apocalyptic number.

1221311203103 is a deficient number, since it is larger than the sum of its proper divisors (920356417).

1221311203103 is an equidigital number, since it uses as much as digits as its factorization.

1221311203103 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 920356416.

The product of its (nonzero) digits is 216, while the sum is 20.

Adding to 1221311203103 its reverse (3013021131221), we get a palindrome (4234332334324).

The spelling of 1221311203103 in words is "one trillion, two hundred twenty-one billion, three hundred eleven million, two hundred three thousand, one hundred three".