645341 has 4 divisors (see below), whose sum is σ = 652092. Its totient is φ = 638592.

The previous prime is 645329. The next prime is 645347. The reversal of 645341 is 143546.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 119716 + 525625 = 346^2 + 725^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645341 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645347) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3230 + ... + 3423.

It is an arithmetic number, because the mean of its divisors is an integer number (163023).

2⁶⁴⁵³⁴¹ is an apocalyptic number.

It is an amenable number.

645341 is a deficient number, since it is larger than the sum of its proper divisors (6751).

645341 is an equidigital number, since it uses as much as digits as its factorization.

645341 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6750.

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

The square root of 645341 is about 803.3311894854. The cubic root of 645341 is about 86.4164495572.

Adding to 645341 its reverse (143546), we get a palindrome (788887).

The spelling of 645341 in words is "six hundred forty-five thousand, three hundred forty-one".