12509533728 has 360 divisors, whose sum is σ = 40254471180. Its totient is φ = 3805885440.

The previous prime is 12509533717. The next prime is 12509533781. The reversal of 12509533728 is 82733590521.

It can be written as a sum of positive squares in 2 ways, for example, as 12430466064 + 79067664 = 111492^2 + 8892^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 27135418 + ... + 27135878.

Almost surely, 2^12509533728 is an apocalyptic number.

12509533728 is a gapful number since it is divisible by the number (18) 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 12509533728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20127235590).

12509533728 is an abundant number, since it is smaller than the sum of its proper divisors (27744937452).

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

12509533728 is a wasteful number, since it uses less digits than its factorization.

12509533728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 550 (or 514 counting only the distinct ones).

The product of its (nonzero) digits is 453600, while the sum is 45.

The spelling of 12509533728 in words is "twelve billion, five hundred nine million, five hundred thirty-three thousand, seven hundred twenty-eight".