640213 has 4 divisors (see below), whose sum is σ = 731680. Its totient is φ = 548748.

The previous prime is 640193. The next prime is 640219. The reversal of 640213 is 312046.

640213 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 640213 - 2⁹ = 639701 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640219) 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, 45723 + ... + 45736.

It is an arithmetic number, because the mean of its divisors is an integer number (182920).

2⁶⁴⁰²¹³ is an apocalyptic number.

It is an amenable number.

640213 is a deficient number, since it is larger than the sum of its proper divisors (91467).

640213 is an equidigital number, since it uses as much as digits as its factorization.

640213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91466.

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

The square root of 640213 is about 800.1331139254. The cubic root of 640213 is about 86.1869468448.

Adding to 640213 its reverse (312046), we get a palindrome (952259).

The spelling of 640213 in words is "six hundred forty thousand, two hundred thirteen".