645708 has 24 divisors (see below), whose sum is σ = 1722112. Its totient is φ = 184464.

The previous prime is 645703. The next prime is 645713. The reversal of 645708 is 807546.

It is a happy number.

645708 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (645703) and next prime (645713).

It is not an unprimeable number, because it can be changed into a prime (645703) 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, 3760 + ... + 3927.

2⁶⁴⁵⁷⁰⁸ is an apocalyptic number.

It is an amenable number.

645708 is an abundant number, since it is smaller than the sum of its proper divisors (1076404).

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

645708 is a wasteful number, since it uses less digits than its factorization.

645708 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7701 (or 7699 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 645708 is about 803.5595808650. The cubic root of 645708 is about 86.4328278889.

The spelling of 645708 in words is "six hundred forty-five thousand, seven hundred eight".