645206 has 8 divisors (see below), whose sum is σ = 994080. Its totient is φ = 313848.

The previous prime is 645187. The next prime is 645233. The reversal of 645206 is 602546.

645206 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 a congruent number.

It is an unprimeable number.

645206 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, 4286 + ... + 4433.

It is an arithmetic number, because the mean of its divisors is an integer number (124260).

2⁶⁴⁵²⁰⁶ is an apocalyptic number.

645206 is a deficient number, since it is larger than the sum of its proper divisors (348874).

645206 is a wasteful number, since it uses less digits than its factorization.

645206 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8758.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 645206 is about 803.2471599701. The cubic root of 645206 is about 86.4104232681.

Adding to 645206 its product of nonzero digits (1440), we get a palindrome (646646).

It can be divided in two parts, 645 and 206, that multiplied together give a triangular number (132870 = T₅₁₅).

The spelling of 645206 in words is "six hundred forty-five thousand, two hundred six".