644030530 has 64 divisors (see below), whose sum is σ = 1376258688. Its totient is φ = 213903360.

The previous prime is 644030477. The next prime is 644030557. The reversal of 644030530 is 35030446.

It is a junction number, because it is equal to n+sod(n) for n = 644030495 and 644030504.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 136389 + ... + 141031.

It is an arithmetic number, because the mean of its divisors is an integer number (21504042).

Almost surely, 2^644030530 is an apocalyptic number.

644030530 is an abundant number, since it is smaller than the sum of its proper divisors (732228158).

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

644030530 is a wasteful number, since it uses less digits than its factorization.

644030530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4771.

The product of its (nonzero) digits is 4320, while the sum is 25.

The square root of 644030530 is about 25377.7565990377. The cubic root of 644030530 is about 863.5791569360.

Adding to 644030530 its reverse (35030446), we get a palindrome (679060976).

The spelling of 644030530 in words is "six hundred forty-four million, thirty thousand, five hundred thirty".