640026064 has 40 divisors (see below), whose sum is σ = 1325325888. Its totient is φ = 298360320.

The previous prime is 640026053. The next prime is 640026103. The reversal of 640026064 is 460620046.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18109 + ... + 40099.

Almost surely, 2^640026064 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 640026064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (662662944).

640026064 is an abundant number, since it is smaller than the sum of its proper divisors (685299824).

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

640026064 is a wasteful number, since it uses less digits than its factorization.

640026064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22123 (or 22117 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 28.

The square root of 640026064 is about 25298.7364111333. The cubic root of 640026064 is about 861.7855744343.

The spelling of 640026064 in words is "six hundred forty million, twenty-six thousand, sixty-four".