12531111320 has 128 divisors (see below), whose sum is σ = 34952601600. Its totient is φ = 3937199616.

The previous prime is 12531111311. The next prime is 12531111343. The reversal of 12531111320 is 2311113521.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 12531111292 and 12531111301.

It is a congruent number.

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, 493577 + ... + 518343.

It is an arithmetic number, because the mean of its divisors is an integer number (273067200).

Almost surely, 2^12531111320 is an apocalyptic number.

12531111320 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 12531111320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17476300800).

12531111320 is an abundant number, since it is smaller than the sum of its proper divisors (22421490280).

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

12531111320 is a wasteful number, since it uses less digits than its factorization.

12531111320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24937 (or 24933 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 20.

Adding to 12531111320 its reverse (2311113521), we get a palindrome (14842224841).

It can be divided in two parts, 125311 and 11320, that added together give a palindrome (136631).

The spelling of 12531111320 in words is "twelve billion, five hundred thirty-one million, one hundred eleven thousand, three hundred twenty".