640524 has 12 divisors (see below), whose sum is σ = 1494584. Its totient is φ = 213504.

The previous prime is 640499. The next prime is 640529. The reversal of 640524 is 425046.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is a self number, because there is not a number n which added to its sum of digits gives 640524.

It is not an unprimeable number, because it can be changed into a prime (640529) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26677 + ... + 26700.

2⁶⁴⁰⁵²⁴ is an apocalyptic number.

It is an amenable number.

640524 is an abundant number, since it is smaller than the sum of its proper divisors (854060).

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

640524 is a wasteful number, since it uses less digits than its factorization.

640524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53384 (or 53382 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 640524 is about 800.3274329923. The cubic root of 640524 is about 86.2009004308.

The spelling of 640524 in words is "six hundred forty thousand, five hundred twenty-four".