1221313202320 has 80 divisors (see below), whose sum is σ = 2880554530032. Its totient is φ = 481481072640.

The previous prime is 1221313202311. The next prime is 1221313202419. The reversal of 1221313202320 is 232023131221.

It can be written as a sum of positive squares in 8 ways, for example, as 56053403536 + 1165259798784 = 236756^2 + 1079472^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×1221313202320² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1221313202291 and 1221313202300.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7989324 + ... + 8140756.

Almost surely, 2^{1221313202320} is an apocalyptic number.

1221313202320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221313202320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1440277265016).

1221313202320 is an abundant number, since it is smaller than the sum of its proper divisors (1659241327712).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221313202320 is a wasteful number, since it uses less digits than its factorization.

1221313202320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152900 (or 152894 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 22.

Adding to 1221313202320 its reverse (232023131221), we get a palindrome (1453336333541).

The spelling of 1221313202320 in words is "one trillion, two hundred twenty-one billion, three hundred thirteen million, two hundred two thousand, three hundred twenty".