64000640 has 64 divisors (see below), whose sum is σ = 166929120. Its totient is φ = 23270400.

The previous prime is 64000637. The next prime is 64000649. The reversal of 64000640 is 4600046.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (64000649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2495 + ... + 11585.

Almost surely, 2^64000640 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 64000640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83464560).

64000640 is an abundant number, since it is smaller than the sum of its proper divisors (102928480).

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

64000640 is a wasteful number, since it uses less digits than its factorization.

64000640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9121 (or 9109 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 64000640 is about 8000.0399999000. The cubic root of 64000640 is about 400.0013333289.

Adding to 64000640 its reverse (4600046), we get a palindrome (68600686).

It can be divided in two parts, 640006 and 40, that added together give a palindrome (640046).

The spelling of 64000640 in words is "sixty-four million, six hundred forty", and thus it is an aban number.