640486 has 16 divisors (see below), whose sum is σ = 1198080. Its totient is φ = 249480.

The previous prime is 640483. The next prime is 640499. The reversal of 640486 is 684046.

It is a super-3 number, since 3×640486³ = 788224951233333768, which contains 333 as substring.

It is an Ulam number.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 1926 + ... + 2233.

It is an arithmetic number, because the mean of its divisors is an integer number (74880).

2⁶⁴⁰⁴⁸⁶ is an apocalyptic number.

640486 is a deficient number, since it is larger than the sum of its proper divisors (557594).

640486 is a wasteful number, since it uses less digits than its factorization.

640486 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4179.

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 640486 is about 800.3036923568. The cubic root of 640486 is about 86.1991957333.

The spelling of 640486 in words is "six hundred forty thousand, four hundred eighty-six".