645924 has 24 divisors (see below), whose sum is σ = 1587040. Its totient is φ = 203904.

The previous prime is 645907. The next prime is 645937. The reversal of 645924 is 429546.

645924 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 645891 and 645900.

It is an unprimeable number.

645924 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, 1189 + ... + 1644.

2⁶⁴⁵⁹²⁴ is an apocalyptic number.

It is an amenable number.

645924 is an abundant number, since it is smaller than the sum of its proper divisors (941116).

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

645924 is a wasteful number, since it uses less digits than its factorization.

645924 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2859 (or 2857 counting only the distinct ones).

The product of its digits is 8640, while the sum is 30.

The square root of 645924 is about 803.6939716086. The cubic root of 645924 is about 86.4424645510.

The spelling of 645924 in words is "six hundred forty-five thousand, nine hundred twenty-four".