64564640 has 96 divisors (see below), whose sum is σ = 184633344. Its totient is φ = 20828160.

The previous prime is 64564637. The next prime is 64564649. The reversal of 64564640 is 4646546.

64564640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 64564640.

It is not an unprimeable number, because it can be changed into a prime (64564649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17345 + ... + 20735.

It is an arithmetic number, because the mean of its divisors is an integer number (1923264).

Almost surely, 2^64564640 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 64564640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (92316672).

64564640 is an abundant number, since it is smaller than the sum of its proper divisors (120068704).

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

64564640 is a wasteful number, since it uses less digits than its factorization.

64564640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3430 (or 3422 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 35.

The square root of 64564640 is about 8035.2125049684. The cubic root of 64564640 is about 401.1728907898.

The spelling of 64564640 in words is "sixty-four million, five hundred sixty-four thousand, six hundred forty".