640518 has 8 divisors (see below), whose sum is σ = 1281048. Its totient is φ = 213504.

The previous prime is 640499. The next prime is 640529. The reversal of 640518 is 815046.

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

640518 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53371 + ... + 53382.

It is an arithmetic number, because the mean of its divisors is an integer number (160131).

2⁶⁴⁰⁵¹⁸ is an apocalyptic number.

640518 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640518 is a wasteful number, since it uses less digits than its factorization.

640518 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106758.

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 640518 is about 800.3236845177. The cubic root of 640518 is about 86.2006312725.

The spelling of 640518 in words is "six hundred forty thousand, five hundred eighteen".