423664 has 10 divisors (see below), whose sum is σ = 820880. Its totient is φ = 211824.

The previous prime is 423649. The next prime is 423667. The reversal of 423664 is 466324.

It is a super-3 number, since 3×423664³ = 228131860073336832, which contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (423667) by changing a digit.

423664 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 as a sum of consecutive naturals, namely, 13224 + ... + 13255.

It is an arithmetic number, because the mean of its divisors is an integer number (82088).

2⁴²³⁶⁶⁴ is an apocalyptic number.

It is an amenable number.

423664 is a deficient number, since it is larger than the sum of its proper divisors (397216).

423664 is a wasteful number, since it uses less digits than its factorization.

423664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26487 (or 26481 counting only the distinct ones).

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

The square root of 423664 is about 650.8947687607. The cubic root of 423664 is about 75.1058653116.

Adding to 423664 its reverse (466324), we get a palindrome (889988).

The spelling of 423664 in words is "four hundred twenty-three thousand, six hundred sixty-four".