51286240728 has 48 divisors (see below), whose sum is σ = 139087325520. Its totient is φ = 17072387136.

The previous prime is 51286240723. The next prime is 51286240757. The reversal of 51286240728 is 82704268215.

51286240728 is a `hidden beast` number, since 5 + 12 + 8 + 624 + 0 + 7 + 2 + 8 = 666.

It is a super-3 number, since 3×51286240728³ (a number of 33 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51286240723) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 425851 + ... + 532842.

It is an arithmetic number, because the mean of its divisors is an integer number (2897652615).

Almost surely, 2^51286240728 is an apocalyptic number.

It is an amenable number.

51286240728 is an abundant number, since it is smaller than the sum of its proper divisors (87801084792).

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

51286240728 is a wasteful number, since it uses less digits than its factorization.

51286240728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 959448 (or 959441 counting only the distinct ones).

The product of its (nonzero) digits is 430080, while the sum is 45.

The spelling of 51286240728 in words is "fifty-one billion, two hundred eighty-six million, two hundred forty thousand, seven hundred twenty-eight".