645440323 has 8 divisors (see below), whose sum is σ = 704606256. Its totient is φ = 586356000.

The previous prime is 645440311. The next prime is 645440347. The reversal of 645440323 is 323044546.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645440323 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645440303) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3228 + ... + 36073.

It is an arithmetic number, because the mean of its divisors is an integer number (88075782).

Almost surely, 2^645440323 is an apocalyptic number.

645440323 is a deficient number, since it is larger than the sum of its proper divisors (59165933).

645440323 is a wasteful number, since it uses less digits than its factorization.

645440323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40805.

The product of its (nonzero) digits is 34560, while the sum is 31.

The square root of 645440323 is about 25405.5175700083. The cubic root of 645440323 is about 864.2088271770.

Adding to 645440323 its reverse (323044546), we get a palindrome (968484869).

The spelling of 645440323 in words is "six hundred forty-five million, four hundred forty thousand, three hundred twenty-three".