644024430 has 96 divisors (see below), whose sum is σ = 2026275264. Its totient is φ = 138544128.

The previous prime is 644024417. The next prime is 644024443. The reversal of 644024430 is 34420446.

It is an interprime number because it is at equal distance from previous prime (644024417) and next prime (644024443).

It is a junction number, because it is equal to n+sod(n) for n = 644024394 and 644024403.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 19357 + ... + 40776.

It is an arithmetic number, because the mean of its divisors is an integer number (21107034).

Almost surely, 2^644024430 is an apocalyptic number.

644024430 is an abundant number, since it is smaller than the sum of its proper divisors (1382250834).

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

644024430 is a wasteful number, since it uses less digits than its factorization.

644024430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60170 (or 60167 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 27.

The square root of 644024430 is about 25377.6364147649. The cubic root of 644024430 is about 863.5764304351.

Adding to 644024430 its reverse (34420446), we get a palindrome (678444876).

The spelling of 644024430 in words is "six hundred forty-four million, twenty-four thousand, four hundred thirty".