640611 has 24 divisors (see below), whose sum is σ = 1010880. Its totient is φ = 389376.

The previous prime is 640589. The next prime is 640613. The reversal of 640611 is 116046.

640611 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 640611 - 2⁵ = 640579 is a prime.

It is not an unprimeable number, because it can be changed into a prime (640613) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8070 + ... + 8148.

It is an arithmetic number, because the mean of its divisors is an integer number (42120).

2⁶⁴⁰⁶¹¹ is an apocalyptic number.

640611 is a deficient number, since it is larger than the sum of its proper divisors (370269).

640611 is a wasteful number, since it uses less digits than its factorization.

640611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155 (or 152 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 640611 is about 800.3817839007. The cubic root of 640611 is about 86.2048030370.

Adding to 640611 its reverse (116046), we get a palindrome (756657).

The spelling of 640611 in words is "six hundred forty thousand, six hundred eleven".