1221313213120 has 224 divisors, whose sum is σ = 3904787045376. Its totient is φ = 351386726400.

The previous prime is 1221313213061. The next prime is 1221313213123. The reversal of 1221313213120 is 213123131221.

It is a tau number, because it is divible by the number of its divisors (224).

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a junction number, because it is equal to n+sod(n) for n = 1221313213091 and 1221313213100.

It is not an unprimeable number, because it can be changed into a prime (1221313213123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1586076 + ... + 2226715.

It is an arithmetic number, because the mean of its divisors is an integer number (17432085024).

Almost surely, 2^{1221313213120} is an apocalyptic number.

1221313213120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221313213120 is an abundant number, since it is smaller than the sum of its proper divisors (2683473832256).

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

1221313213120 is a wasteful number, since it uses less digits than its factorization.

1221313213120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3812839 (or 3812829 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 22.

Adding to 1221313213120 its reverse (213123131221), we get a palindrome (1434436344341).

The spelling of 1221313213120 in words is "one trillion, two hundred twenty-one billion, three hundred thirteen million, two hundred thirteen thousand, one hundred twenty".