640210 has 16 divisors (see below), whose sum is σ = 1169496. Its totient is φ = 252288.

The previous prime is 640193. The next prime is 640219. The reversal of 640210 is 12046.

It can be written as a sum of positive squares in 4 ways, for example, as 603729 + 36481 = 777^2 + 191^2 .

It is not an unprimeable number, because it can be changed into a prime (640219) by changing a digit.

640210 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 292 + ... + 1168.

2⁶⁴⁰²¹⁰ is an apocalyptic number.

640210 is a deficient number, since it is larger than the sum of its proper divisors (529286).

640210 is a wasteful number, since it uses less digits than its factorization.

640210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 957.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 640210 is about 800.1312392352. The cubic root of 640210 is about 86.1868122223.

Adding to 640210 its reverse (12046), we get a palindrome (652256).

The spelling of 640210 in words is "six hundred forty thousand, two hundred ten".