1221321201303 has 64 divisors (see below), whose sum is σ = 1964254924800. Its totient is φ = 660521072640.

The previous prime is 1221321201271. The next prime is 1221321201323. The reversal of 1221321201303 is 3031021231221.

It is not a de Polignac number, because 1221321201303 - 2⁵ = 1221321201271 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 1221321201303.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221321201323) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3910978 + ... + 4211696.

It is an arithmetic number, because the mean of its divisors is an integer number (30691483200).

Almost surely, 2^{1221321201303} is an apocalyptic number.

1221321201303 is a deficient number, since it is larger than the sum of its proper divisors (742933723497).

1221321201303 is a wasteful number, since it uses less digits than its factorization.

1221321201303 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300912.

The product of its (nonzero) digits is 432, while the sum is 21.

Adding to 1221321201303 its reverse (3031021231221), we get a palindrome (4252342432524).

The spelling of 1221321201303 in words is "one trillion, two hundred twenty-one billion, three hundred twenty-one million, two hundred one thousand, three hundred three".