646603 has 4 divisors (see below), whose sum is σ = 649528. Its totient is φ = 643680.

The previous prime is 646577. The next prime is 646609. The reversal of 646603 is 306646.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 646603 - 2⁵ = 646571 is a prime.

It is a Duffinian number.

646603 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (646609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1101 + ... + 1582.

It is an arithmetic number, because the mean of its divisors is an integer number (162382).

2⁶⁴⁶⁶⁰³ is an apocalyptic number.

646603 is a deficient number, since it is larger than the sum of its proper divisors (2925).

646603 is a wasteful number, since it uses less digits than its factorization.

646603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2924.

The product of its (nonzero) digits is 2592, while the sum is 25.

The square root of 646603 is about 804.1162851230. The cubic root of 646603 is about 86.4727435925.

The spelling of 646603 in words is "six hundred forty-six thousand, six hundred three".