644042424 has 32 divisors (see below), whose sum is σ = 1653624720. Its totient is φ = 208878336.

The previous prime is 644042423. The next prime is 644042429. The reversal of 644042424 is 424240446.

644042424 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 644042391 and 644042400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644042423) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 361749 + ... + 363524.

Almost surely, 2^644042424 is an apocalyptic number.

It is an amenable number.

644042424 is an abundant number, since it is smaller than the sum of its proper divisors (1009582296).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644042424 is a wasteful number, since it uses less digits than its factorization.

644042424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 725319 (or 725315 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 30.

The square root of 644042424 is about 25377.9909370305. The cubic root of 644042424 is about 863.5844731163.

The spelling of 644042424 in words is "six hundred forty-four million, forty-two thousand, four hundred twenty-four".