64591728 has 80 divisors (see below), whose sum is σ = 178488576. Its totient is φ = 20078080.

The previous prime is 64591711. The next prime is 64591733. The reversal of 64591728 is 82719546.

It is a self number, because there is not a number n which added to its sum of digits gives 64591728.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 44551 + ... + 45977.

Almost surely, 2^64591728 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 64591728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89244288).

64591728 is an abundant number, since it is smaller than the sum of its proper divisors (113896848).

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

64591728 is a wasteful number, since it uses less digits than its factorization.

64591728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1502 (or 1496 counting only the distinct ones).

The product of its digits is 120960, while the sum is 42.

The square root of 64591728 is about 8036.8979090194. The cubic root of 64591728 is about 401.2289867782.

The spelling of 64591728 in words is "sixty-four million, five hundred ninety-one thousand, seven hundred twenty-eight".