645873 has 16 divisors (see below), whose sum is σ = 907200. Its totient is φ = 408320.

The previous prime is 645857. The next prime is 645877. The reversal of 645873 is 378546.

It is a cyclic number.

It is not a de Polignac number, because 645873 - 2⁴ = 645857 is a prime.

Its product of digits (20160) is a multiple of the sum of its prime divisors (192).

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 645873.

It is not an unprimeable number, because it can be changed into a prime (645877) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7213 + ... + 7301.

It is an arithmetic number, because the mean of its divisors is an integer number (56700).

2⁶⁴⁵⁸⁷³ is an apocalyptic number.

It is an amenable number.

645873 is a deficient number, since it is larger than the sum of its proper divisors (261327).

645873 is a wasteful number, since it uses less digits than its factorization.

645873 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192.

The product of its digits is 20160, while the sum is 33.

The square root of 645873 is about 803.6622424875. The cubic root of 645873 is about 86.4401894218.

The spelling of 645873 in words is "six hundred forty-five thousand, eight hundred seventy-three".