64861728 has 24 divisors (see below), whose sum is σ = 170262288. Its totient is φ = 21620544.

The previous prime is 64861717. The next prime is 64861733. The reversal of 64861728 is 82716846.

It is a tau number, because it is divible by the number of its divisors (24).

It is a self number, because there is not a number n which added to its sum of digits gives 64861728.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 337726 + ... + 337917.

It is an arithmetic number, because the mean of its divisors is an integer number (7094262).

Almost surely, 2^64861728 is an apocalyptic number.

It is an amenable number.

64861728 is an abundant number, since it is smaller than the sum of its proper divisors (105400560).

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

64861728 is a wasteful number, since it uses less digits than its factorization.

64861728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 675656 (or 675648 counting only the distinct ones).

The product of its digits is 129024, while the sum is 42.

The square root of 64861728 is about 8053.6779175728. The cubic root of 64861728 is about 401.7872689469.

The spelling of 64861728 in words is "sixty-four million, eight hundred sixty-one thousand, seven hundred twenty-eight".