640670500 has 96 divisors (see below), whose sum is σ = 1559900160. Its totient is φ = 228441600.

The previous prime is 640670491. The next prime is 640670507. The reversal of 640670500 is 5076046.

It is not an unprimeable number, because it can be changed into a prime (640670507) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 159517 + ... + 163483.

It is an arithmetic number, because the mean of its divisors is an integer number (16248960).

Almost surely, 2^640670500 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 640670500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (779950080).

640670500 is an abundant number, since it is smaller than the sum of its proper divisors (919229660).

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

640670500 is a wasteful number, since it uses less digits than its factorization.

640670500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4022 (or 4010 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 28.

The square root of 640670500 is about 25311.4697321195. The cubic root of 640670500 is about 862.0747185731.

The spelling of 640670500 in words is "six hundred forty million, six hundred seventy thousand, five hundred".