646423 has 2 divisors, whose sum is σ = 646424. Its totient is φ = 646422.

The previous prime is 646421. The next prime is 646433. The reversal of 646423 is 324646.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 646423 - 2¹ = 646421 is a prime.

Together with 646421, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323211 + 323212.

It is an arithmetic number, because the mean of its divisors is an integer number (323212).

2⁶⁴⁶⁴²³ is an apocalyptic number.

646423 is a deficient number, since it is larger than the sum of its proper divisors (1).

646423 is an equidigital number, since it uses as much as digits as its factorization.

646423 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3456, while the sum is 25.

The square root of 646423 is about 804.0043532220. The cubic root of 646423 is about 86.4647188136.

The spelling of 646423 in words is "six hundred forty-six thousand, four hundred twenty-three".