640541 has 4 divisors (see below), whose sum is σ = 698784. Its totient is φ = 582300.

The previous prime is 640531. The next prime is 640579. The reversal of 640541 is 145046.

It is a happy number.

640541 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 640541 - 2⁶ = 640477 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640531) 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, 29105 + ... + 29126.

It is an arithmetic number, because the mean of its divisors is an integer number (174696).

2⁶⁴⁰⁵⁴¹ is an apocalyptic number.

It is an amenable number.

640541 is a deficient number, since it is larger than the sum of its proper divisors (58243).

640541 is a wasteful number, since it uses less digits than its factorization.

640541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58242.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 640541 is about 800.3380535749. The cubic root of 640541 is about 86.2016630368.

Adding to 640541 its reverse (145046), we get a palindrome (785587).

It can be divided in two parts, 6405 and 41, that added together give a palindrome (6446).

The spelling of 640541 in words is "six hundred forty thousand, five hundred forty-one".