640503 has 6 divisors (see below), whose sum is σ = 925184. Its totient is φ = 426996.

The previous prime is 640499. The next prime is 640529. The reversal of 640503 is 305046.

It is a happy number.

It is not a de Polignac number, because 640503 - 2² = 640499 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 640503.

It is not an unprimeable number, because it can be changed into a prime (640583) 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 5 ways as a sum of consecutive naturals, for example, 35575 + ... + 35592.

2⁶⁴⁰⁵⁰³ is an apocalyptic number.

640503 is a deficient number, since it is larger than the sum of its proper divisors (284681).

640503 is a wasteful number, since it uses less digits than its factorization.

640503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71173 (or 71170 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 18.

The square root of 640503 is about 800.3143132545. The cubic root of 640503 is about 86.1999583694.

Adding to 640503 its reverse (305046), we get a palindrome (945549).

The spelling of 640503 in words is "six hundred forty thousand, five hundred three".