12756457728 has 486 divisors, whose sum is σ = 45299533734. Its totient is φ = 3441844224.

The previous prime is 12756457691. The next prime is 12756457729. The reversal of 12756457728 is 82775465721.

12756457728 is a `hidden beast` number, since 1 + 2 + 7 + 5 + 64 + 577 + 2 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 6887672064 + 5868785664 = 82992^2 + 76608^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12756457729) by changing a digit.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 40755300 + ... + 40755612.

Almost surely, 2^12756457728 is an apocalyptic number.

12756457728 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 12756457728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22649766867).

12756457728 is an abundant number, since it is smaller than the sum of its proper divisors (32543076006).

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

12756457728 is a wasteful number, since it uses less digits than its factorization.

12756457728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 387 (or 344 counting only the distinct ones).

The product of its digits is 6585600, while the sum is 54.

The spelling of 12756457728 in words is "twelve billion, seven hundred fifty-six million, four hundred fifty-seven thousand, seven hundred twenty-eight".