645343 has 4 divisors (see below), whose sum is σ = 651168. Its totient is φ = 639520.

The previous prime is 645329. The next prime is 645347. The reversal of 645343 is 343546.

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

It is a cyclic number.

It is not a de Polignac number, because 645343 - 2¹⁷ = 514271 is a prime.

It is a d-powerful number, because it can be written as 6⁶ + 4⁶ + 3¹⁰ + 5 + 4⁶ + 3¹² .

It is a Duffinian 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 pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2743 + ... + 2968.

It is an arithmetic number, because the mean of its divisors is an integer number (162792).

2⁶⁴⁵³⁴³ is an apocalyptic number.

645343 is a deficient number, since it is larger than the sum of its proper divisors (5825).

645343 is a wasteful number, since it uses less digits than its factorization.

645343 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5824.

The product of its digits is 4320, while the sum is 25.

The square root of 645343 is about 803.3324343010. The cubic root of 645343 is about 86.4165388292.

Adding to 645343 its reverse (343546), we get a palindrome (988889).

The spelling of 645343 in words is "six hundred forty-five thousand, three hundred forty-three".