1311221223120 has 160 divisors (see below), whose sum is σ = 4098303406080. Its totient is φ = 346777804800.

The previous prime is 1311221223119. The next prime is 1311221223127. The reversal of 1311221223120 is 213221221131.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311221223127) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 105728920 + ... + 105741320.

It is an arithmetic number, because the mean of its divisors is an integer number (25614396288).

Almost surely, 2^{1311221223120} is an apocalyptic number.

1311221223120 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 1311221223120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2049151703040).

1311221223120 is an abundant number, since it is smaller than the sum of its proper divisors (2787082182960).

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

1311221223120 is a wasteful number, since it uses less digits than its factorization.

1311221223120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16013 (or 16007 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 21.

Adding to 1311221223120 its reverse (213221221131), we get a palindrome (1524442444251).

The spelling of 1311221223120 in words is "one trillion, three hundred eleven billion, two hundred twenty-one million, two hundred twenty-three thousand, one hundred twenty".