640225 has 6 divisors (see below), whose sum is σ = 793910. Its totient is φ = 512160.

The previous prime is 640223. The next prime is 640229. The reversal of 640225 is 522046.

It can be written as a sum of positive squares in 3 ways, for example, as 219024 + 421201 = 468^2 + 649^2 .

It is not a de Polignac number, because 640225 - 2¹ = 640223 is a prime.

It is not an unprimeable number, because it can be changed into a prime (640223) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12780 + ... + 12829.

2⁶⁴⁰²²⁵ is an apocalyptic number.

It is an amenable number.

640225 is a deficient number, since it is larger than the sum of its proper divisors (153685).

640225 is a wasteful number, since it uses less digits than its factorization.

640225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25619 (or 25614 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 640225 is about 800.1406126426. The cubic root of 640225 is about 86.1874853306.

The spelling of 640225 in words is "six hundred forty thousand, two hundred twenty-five".