645328 has 20 divisors (see below), whose sum is σ = 1275588. Its totient is φ = 316160.

The previous prime is 645313. The next prime is 645329. The reversal of 645328 is 823546.

It can be written as a sum of positive squares in 2 ways, for example, as 166464 + 478864 = 408^2 + 692^2 .

It is a junction number, because it is equal to n+sod(n) for n = 645296 and 645305.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645329) by changing a digit.

645328 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 3 ways as a sum of consecutive naturals, for example, 468 + ... + 1228.

2⁶⁴⁵³²⁸ is an apocalyptic number.

It is an amenable number.

645328 is a deficient number, since it is larger than the sum of its proper divisors (630260).

645328 is a wasteful number, since it uses less digits than its factorization.

645328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 822 (or 816 counting only the distinct ones).

The product of its digits is 5760, while the sum is 28.

The square root of 645328 is about 803.3230981367. The cubic root of 645328 is about 86.4158692844.

The spelling of 645328 in words is "six hundred forty-five thousand, three hundred twenty-eight".