646424 has 8 divisors (see below), whose sum is σ = 1212060. Its totient is φ = 323208.

The previous prime is 646423. The next prime is 646433. The reversal of 646424 is 424646.

646424 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (8).

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 646393 and 646402.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 646424.

It is not an unprimeable number, because it can be changed into a prime (646421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40394 + ... + 40409.

2⁶⁴⁶⁴²⁴ is an apocalyptic number.

It is an amenable number.

646424 is a deficient number, since it is larger than the sum of its proper divisors (565636).

646424 is a wasteful number, since it uses less digits than its factorization.

646424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80809 (or 80805 counting only the distinct ones).

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

The square root of 646424 is about 804.0049751090. The cubic root of 646424 is about 86.4647633998.

It can be divided in two parts, 64642 and 4, that added together give a palindrome (64646).

The spelling of 646424 in words is "six hundred forty-six thousand, four hundred twenty-four".