645201 has 12 divisors (see below), whose sum is σ = 987012. Its totient is φ = 404736.

The previous prime is 645187. The next prime is 645233. The reversal of 645201 is 102546.

It is a happy number.

645201 is a `hidden beast` number, since 645 + 20 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 540225 + 104976 = 735^2 + 324^2 .

It is not a de Polignac number, because 645201 - 2⁶ = 645137 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645901) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1956 + ... + 2261.

It is an arithmetic number, because the mean of its divisors is an integer number (82251).

2⁶⁴⁵²⁰¹ is an apocalyptic number.

It is an amenable number.

645201 is a deficient number, since it is larger than the sum of its proper divisors (341811).

645201 is a wasteful number, since it uses less digits than its factorization.

645201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4240 (or 4237 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 645201 is about 803.2440475970. The cubic root of 645201 is about 86.4102000561.

Adding to 645201 its reverse (102546), we get a palindrome (747747).

The spelling of 645201 in words is "six hundred forty-five thousand, two hundred one".