1311232120 has 64 divisors (see below), whose sum is σ = 3229100640. Its totient is φ = 475238400.

The previous prime is 1311232057. The next prime is 1311232121. The reversal of 1311232120 is 212321131.

It is a junction number, because it is equal to n+sod(n) for n = 1311232094 and 1311232103.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311232121) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 132960 + ... + 142480.

Almost surely, 2^1311232120 is an apocalyptic number.

1311232120 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 1311232120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1614550320).

1311232120 is an abundant number, since it is smaller than the sum of its proper divisors (1917868520).

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

1311232120 is a wasteful number, since it uses less digits than its factorization.

1311232120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9856 (or 9852 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 1311232120 is about 36210.9392311219. The cubic root of 1311232120 is about 1094.5271187075.

Adding to 1311232120 its reverse (212321131), we get a palindrome (1523553251).

The spelling of 1311232120 in words is "one billion, three hundred eleven million, two hundred thirty-two thousand, one hundred twenty".