645323 has 4 divisors (see below), whose sum is σ = 737520. Its totient is φ = 553128.

The previous prime is 645313. The next prime is 645329. The reversal of 645323 is 323546.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 323546 = 2 ⋅161773.

It is a cyclic number.

It is not a de Polignac number, because 645323 - 2⁸ = 645067 is a prime.

It is not an unprimeable number, because it can be changed into a prime (645329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46088 + ... + 46101.

It is an arithmetic number, because the mean of its divisors is an integer number (184380).

2⁶⁴⁵³²³ is an apocalyptic number.

645323 is a deficient number, since it is larger than the sum of its proper divisors (92197).

645323 is an equidigital number, since it uses as much as digits as its factorization.

645323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92196.

The product of its digits is 2160, while the sum is 23.

The square root of 645323 is about 803.3199860579. The cubic root of 645323 is about 86.4156461005.

Adding to 645323 its reverse (323546), we get a palindrome (968869).

It can be divided in two parts, 645 and 323, that multiplied together give a triangular number (208335 = T₆₄₅).

The spelling of 645323 in words is "six hundred forty-five thousand, three hundred twenty-three".