645008 has 40 divisors (see below), whose sum is σ = 1541568. Its totient is φ = 254592.

The previous prime is 644999. The next prime is 645011. The reversal of 645008 is 800546.

645008 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

645008 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1235 + ... + 1677.

2⁶⁴⁵⁰⁰⁸ 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 645008, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (770784).

645008 is an abundant number, since it is smaller than the sum of its proper divisors (896560).

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

645008 is a wasteful number, since it uses less digits than its factorization.

645008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 471 (or 465 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 645008 is about 803.1239007775. The cubic root of 645008 is about 86.4015831900.

The spelling of 645008 in words is "six hundred forty-five thousand, eight".