51985728 has 84 divisors (see below), whose sum is σ = 157802580. Its totient is φ = 16306176.

The previous prime is 51985723. The next prime is 51985751. The reversal of 51985728 is 82758915.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 15116544 + 36869184 = 3888^2 + 6072^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51985721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7138 + ... + 12446.

Almost surely, 2^51985728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51985728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (78901290).

51985728 is an abundant number, since it is smaller than the sum of its proper divisors (105816852).

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

51985728 is a wasteful number, since it uses less digits than its factorization.

51985728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5344 (or 5331 counting only the distinct ones).

The product of its digits is 201600, while the sum is 45.

The square root of 51985728 is about 7210.1128978678. The cubic root of 51985728 is about 373.2169648654.

The spelling of 51985728 in words is "fifty-one million, nine hundred eighty-five thousand, seven hundred twenty-eight".