643603 has 8 divisors (see below), whose sum is σ = 689040. Its totient is φ = 601120.

The previous prime is 643589. The next prime is 643619. The reversal of 643603 is 306346.

It is not a de Polignac number, because 643603 - 2¹⁷ = 512531 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643633) 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, 4848 + ... + 4978.

It is an arithmetic number, because the mean of its divisors is an integer number (86130).

2⁶⁴³⁶⁰³ is an apocalyptic number.

643603 is a deficient number, since it is larger than the sum of its proper divisors (45437).

643603 is an equidigital number, since it uses as much as digits as its factorization.

643603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182 (or 148 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 22.

The square root of 643603 is about 802.2487145518. The cubic root of 643603 is about 86.3388023283.

Adding to 643603 its reverse (306346), we get a palindrome (949949).

The spelling of 643603 in words is "six hundred forty-three thousand, six hundred three".