1311222120 has 128 divisors (see below), whose sum is σ = 4316457600. Its totient is φ = 316652544.

The previous prime is 1311222119. The next prime is 1311222161. The reversal of 1311222120 is 212221131.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 1311222120.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 74751 + ... + 90609.

It is an arithmetic number, because the mean of its divisors is an integer number (33722325).

Almost surely, 2^1311222120 is an apocalyptic number.

1311222120 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 1311222120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2158228800).

1311222120 is an abundant number, since it is smaller than the sum of its proper divisors (3005235480).

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

1311222120 is a wasteful number, since it uses less digits than its factorization.

1311222120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15939 (or 15935 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 1311222120 is about 36210.8011510378. The cubic root of 1311222120 is about 1094.5243362612.

Adding to 1311222120 its reverse (212221131), we get a palindrome (1523443251).

The spelling of 1311222120 in words is "one billion, three hundred eleven million, two hundred twenty-two thousand, one hundred twenty".