640563 has 32 divisors (see below), whose sum is σ = 1105920. Its totient is φ = 320160.

The previous prime is 640531. The next prime is 640579. The reversal of 640563 is 365046.

640563 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 640563 - 2⁵ = 640531 is a prime.

It is not an unprimeable number, because it can be changed into a prime (640583) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10828 + ... + 10886.

It is an arithmetic number, because the mean of its divisors is an integer number (34560).

2⁶⁴⁰⁵⁶³ is an apocalyptic number.

640563 is a deficient number, since it is larger than the sum of its proper divisors (465357).

640563 is a wasteful number, since it uses less digits than its factorization.

640563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127.

The product of its (nonzero) digits is 2160, while the sum is 24.

The square root of 640563 is about 800.3517976490. The cubic root of 640563 is about 86.2026499186.

The spelling of 640563 in words is "six hundred forty thousand, five hundred sixty-three".