645165 has 32 divisors (see below), whose sum is σ = 1180800. Its totient is φ = 338256.

The previous prime is 645149. The next prime is 645179. The reversal of 645165 is 561546.

It is a happy number.

645165 is a `hidden beast` number, since 645 + 16 + 5 = 666.

645165 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 645165 - 2⁴ = 645149 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 645165.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10906 + ... + 10964.

It is an arithmetic number, because the mean of its divisors is an integer number (36900).

2⁶⁴⁵¹⁶⁵ is an apocalyptic number.

It is an amenable number.

645165 is a deficient number, since it is larger than the sum of its proper divisors (535635).

645165 is an frugal number, since it uses more digits than its factorization.

645165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85 (or 67 counting only the distinct ones).

The product of its digits is 3600, while the sum is 27.

The square root of 645165 is about 803.2216381547. The cubic root of 645165 is about 86.4085928954.

The spelling of 645165 in words is "six hundred forty-five thousand, one hundred sixty-five".