645205 has 8 divisors (see below), whose sum is σ = 844704. Its totient is φ = 469200.

The previous prime is 645187. The next prime is 645233. The reversal of 645205 is 502546.

645205 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 645205 - 2⁷ = 645077 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5811 + ... + 5920.

It is an arithmetic number, because the mean of its divisors is an integer number (105588).

2⁶⁴⁵²⁰⁵ is an apocalyptic number.

It is an amenable number.

645205 is a deficient number, since it is larger than the sum of its proper divisors (199499).

645205 is a wasteful number, since it uses less digits than its factorization.

645205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11747.

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 645205 is about 803.2465374964. The cubic root of 645205 is about 86.4103786258.

The spelling of 645205 in words is "six hundred forty-five thousand, two hundred five".