640919600 has 60 divisors (see below), whose sum is σ = 1548055680. Its totient is φ = 254995200.

The previous prime is 640919599. The next prime is 640919623. The reversal of 640919600 is 6919046.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 72206 + ... + 80594.

It is an arithmetic number, because the mean of its divisors is an integer number (25800928).

Almost surely, 2^640919600 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 640919600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (774027840).

640919600 is an abundant number, since it is smaller than the sum of its proper divisors (907136080).

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

640919600 is a wasteful number, since it uses less digits than its factorization.

640919600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8598 (or 8587 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 35.

The square root of 640919600 is about 25316.3899480159. The cubic root of 640919600 is about 862.1864322579.

The spelling of 640919600 in words is "six hundred forty million, nine hundred nineteen thousand, six hundred".