640550 has 24 divisors (see below), whose sum is σ = 1245456. Its totient is φ = 244640.

The previous prime is 640531. The next prime is 640579. The reversal of 640550 is 55046.

It is a Curzon 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 640550.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 872 + ... + 1428.

It is an arithmetic number, because the mean of its divisors is an integer number (51894).

2⁶⁴⁰⁵⁵⁰ is an apocalyptic number.

640550 is a deficient number, since it is larger than the sum of its proper divisors (604906).

640550 is a wasteful number, since it uses less digits than its factorization.

640550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 592 (or 587 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 20.

The square root of 640550 is about 800.3436761792. The cubic root of 640550 is about 86.2020667639.

Adding to 640550 its reverse (55046), we get a palindrome (695596).

The spelling of 640550 in words is "six hundred forty thousand, five hundred fifty".