640207 has 6 divisors (see below), whose sum is σ = 654464. Its totient is φ = 626220.

The previous prime is 640193. The next prime is 640219. The reversal of 640207 is 702046.

It is not a de Polignac number, because 640207 - 2¹¹ = 638159 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4978 + ... + 5104.

2⁶⁴⁰²⁰⁷ is an apocalyptic number.

640207 is a deficient number, since it is larger than the sum of its proper divisors (14257).

640207 is an equidigital number, since it uses as much as digits as its factorization.

640207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 269 (or 198 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 19.

The square root of 640207 is about 800.1293645405. The cubic root of 640207 is about 86.1866775994.

The spelling of 640207 in words is "six hundred forty thousand, two hundred seven".