664424 has 24 divisors (see below), whose sum is σ = 1310610. Its totient is φ = 315744.

The previous prime is 664421. The next prime is 664427. The reversal of 664424 is 424466.

It is an interprime number because it is at equal distance from previous prime (664421) and next prime (664427).

It can be written as a sum of positive squares in only one way, i.e., 611524 + 52900 = 782^2 + 230^2 .

It is a plaindrome in base 9.

It is a junction number, because it is equal to n+sod(n) for n = 664393 and 664402.

It is not an unprimeable number, because it can be changed into a prime (664421) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4154 + ... + 4310.

2⁶⁶⁴⁴²⁴ is an apocalyptic number.

It is an amenable number.

664424 is a deficient number, since it is larger than the sum of its proper divisors (646186).

664424 is a wasteful number, since it uses less digits than its factorization.

664424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209 (or 182 counting only the distinct ones).

The product of its digits is 4608, while the sum is 26.

The square root of 664424 is about 815.1220767468. The cubic root of 664424 is about 87.2599789354.

The spelling of 664424 in words is "six hundred sixty-four thousand, four hundred twenty-four".