640485 has 24 divisors (see below), whose sum is σ = 1139424. Its totient is φ = 332640.

The previous prime is 640483. The next prime is 640499. The reversal of 640485 is 584046.

It is not a de Polignac number, because 640485 - 2¹ = 640483 is a prime.

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 640485.

It is not an unprimeable number, because it can be changed into a prime (640483) 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 23 ways as a sum of consecutive naturals, for example, 1770 + ... + 2100.

It is an arithmetic number, because the mean of its divisors is an integer number (47476).

2⁶⁴⁰⁴⁸⁵ is an apocalyptic number.

It is an amenable number.

640485 is a deficient number, since it is larger than the sum of its proper divisors (498939).

640485 is a wasteful number, since it uses less digits than its factorization.

640485 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 385 (or 382 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 640485 is about 800.3030675938. The cubic root of 640485 is about 86.1991508719.

The spelling of 640485 in words is "six hundred forty thousand, four hundred eighty-five".