640135 has 12 divisors (see below), whose sum is σ = 817848. Its totient is φ = 480896.

The previous prime is 640127. The next prime is 640139. The reversal of 640135 is 531046.

It is not a de Polignac number, because 640135 - 2³ = 640127 is a prime.

It is a Duffinian number.

640135 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640139) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1224 + ... + 1666.

It is an arithmetic number, because the mean of its divisors is an integer number (68154).

2⁶⁴⁰¹³⁵ is an apocalyptic number.

640135 is a deficient number, since it is larger than the sum of its proper divisors (177713).

640135 is a wasteful number, since it uses less digits than its factorization.

640135 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 482 (or 465 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 640135 is about 800.0843705510. The cubic root of 640135 is about 86.1834465228.

The spelling of 640135 in words is "six hundred forty thousand, one hundred thirty-five".