64728756 has 18 divisors (see below), whose sum is σ = 163620002. Its totient is φ = 21576240.

The previous prime is 64728751. The next prime is 64728757. The reversal of 64728756 is 65782746.

It can be written as a sum of positive squares in only one way, i.e., 46376100 + 18352656 = 6810^2 + 4284^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64728751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 898975 + ... + 899046.

Almost surely, 2^64728756 is an apocalyptic number.

It is an amenable number.

64728756 is an abundant number, since it is smaller than the sum of its proper divisors (98891246).

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

64728756 is a wasteful number, since it uses less digits than its factorization.

64728756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1798031 (or 1798026 counting only the distinct ones).

The product of its digits is 564480, while the sum is 45.

The square root of 64728756 is about 8045.4183234932. The cubic root of 64728756 is about 401.5125152024.

It can be divided in two parts, 647 and 28756, that added together give a triangular number (29403 = T₂₄₂).

The spelling of 64728756 in words is "sixty-four million, seven hundred twenty-eight thousand, seven hundred fifty-six".