645567 has 8 divisors (see below), whose sum is σ = 927024. Its totient is φ = 397248.

The previous prime is 645529. The next prime is 645571. The reversal of 645567 is 765546.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 645567 - 2⁶ = 645503 is a prime.

645567 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645527) 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, 8238 + ... + 8315.

It is an arithmetic number, because the mean of its divisors is an integer number (115878).

2⁶⁴⁵⁵⁶⁷ is an apocalyptic number.

645567 is a deficient number, since it is larger than the sum of its proper divisors (281457).

645567 is a wasteful number, since it uses less digits than its factorization.

645567 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16569.

The product of its digits is 25200, while the sum is 33.

The square root of 645567 is about 803.4718414481. The cubic root of 645567 is about 86.4265361306.

The spelling of 645567 in words is "six hundred forty-five thousand, five hundred sixty-seven".