644030532 has 72 divisors (see below), whose sum is σ = 1672690656. Its totient is φ = 208859904.

The previous prime is 644030477. The next prime is 644030557. The reversal of 644030532 is 235030446.

644030532 is a `hidden beast` number, since 64 + 40 + 30 + 532 = 666.

It is a super-2 number, since 2×644030532² = 829550652296406048, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 644030496 and 644030505.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 198588 + ... + 201804.

Almost surely, 2^644030532 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644030532, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (836345328).

644030532 is an abundant number, since it is smaller than the sum of its proper divisors (1028660124).

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

644030532 is a wasteful number, since it uses less digits than its factorization.

644030532 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3377 (or 3372 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 27.

The square root of 644030532 is about 25377.7566384423. The cubic root of 644030532 is about 863.5791578299.

Adding to 644030532 its reverse (235030446), we get a palindrome (879060978).

The spelling of 644030532 in words is "six hundred forty-four million, thirty thousand, five hundred thirty-two".