643534630 has 16 divisors (see below), whose sum is σ = 1169833104. Its totient is φ = 254864800.

The previous prime is 643534613. The next prime is 643534631. The reversal of 643534630 is 36435346.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643534631) 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, 317572 + ... + 319591.

It is an arithmetic number, because the mean of its divisors is an integer number (73114569).

Almost surely, 2^643534630 is an apocalyptic number.

643534630 is a deficient number, since it is larger than the sum of its proper divisors (526298474).

643534630 is a wasteful number, since it uses less digits than its factorization.

643534630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 637271.

The product of its (nonzero) digits is 77760, while the sum is 34.

The square root of 643534630 is about 25367.9843503578. The cubic root of 643534630 is about 863.3574496062.

Adding to 643534630 its reverse (36435346), we get a palindrome (679969976).

The spelling of 643534630 in words is "six hundred forty-three million, five hundred thirty-four thousand, six hundred thirty".