51728868 has 72 divisors (see below), whose sum is σ = 142789920. Its totient is φ = 16329600.

The previous prime is 51728861. The next prime is 51728869. The reversal of 51728868 is 86882715.

It is a super-2 number, since 2×51728868² = 5351751569122848, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (51728861) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17068 + ... + 19868.

Almost surely, 2^51728868 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 51728868, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (71394960).

51728868 is an abundant number, since it is smaller than the sum of its proper divisors (91061052).

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

51728868 is a wasteful number, since it uses less digits than its factorization.

51728868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2839 (or 2825 counting only the distinct ones).

The product of its digits is 215040, while the sum is 45.

The square root of 51728868 is about 7192.2783594630. The cubic root of 51728868 is about 372.6012649027.

The spelling of 51728868 in words is "fifty-one million, seven hundred twenty-eight thousand, eight hundred sixty-eight".