643652 has 12 divisors (see below), whose sum is σ = 1157100. Its totient is φ = 313056.

The previous prime is 643651. The next prime is 643661. The reversal of 643652 is 256346.

It can be written as a sum of positive squares in 2 ways, for example, as 264196 + 379456 = 514^2 + 616^2 .

It is a d-powerful number, because it can be written as 6 + 4² + 6⁴ + 3¹² + 5⁷ + 2¹⁵ .

It is a nialpdrome in base 15.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 643652.

It is not an unprimeable number, because it can be changed into a prime (643651) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2027 + ... + 2322.

It is an arithmetic number, because the mean of its divisors is an integer number (96425).

2⁶⁴³⁶⁵² is an apocalyptic number.

It is an amenable number.

643652 is a deficient number, since it is larger than the sum of its proper divisors (513448).

643652 is a wasteful number, since it uses less digits than its factorization.

643652 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4390 (or 4388 counting only the distinct ones).

The product of its digits is 4320, while the sum is 26.

The square root of 643652 is about 802.2792531282. The cubic root of 643652 is about 86.3409933756.

Adding to 643652 its reverse (256346), we get a palindrome (899998).

The spelling of 643652 in words is "six hundred forty-three thousand, six hundred fifty-two".