640006 has 8 divisors (see below), whose sum is σ = 970200. Its totient is φ = 316608.

The previous prime is 639997. The next prime is 640007. The reversal of 640006 is 600046.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a nialpdrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1456 + ... + 1843.

It is an arithmetic number, because the mean of its divisors is an integer number (121275).

2⁶⁴⁰⁰⁰⁶ is an apocalyptic number.

640006 is a deficient number, since it is larger than the sum of its proper divisors (330194).

640006 is a wasteful number, since it uses less digits than its factorization.

640006 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3398.

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 640006 is about 800.0037499912. The cubic root of 640006 is about 86.1776569048.

The spelling of 640006 in words is "six hundred forty thousand, six".