640346 has 16 divisors (see below), whose sum is σ = 1119744. Its totient is φ = 268944.

The previous prime is 640333. The next prime is 640363. The reversal of 640346 is 643046.

640346 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 640346.

It is an unprimeable number.

640346 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 311 + ... + 1173.

It is an arithmetic number, because the mean of its divisors is an integer number (69984).

2⁶⁴⁰³⁴⁶ is an apocalyptic number.

640346 is a deficient number, since it is larger than the sum of its proper divisors (479398).

640346 is a wasteful number, since it uses less digits than its factorization.

640346 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 925.

The product of its (nonzero) digits is 1728, while the sum is 23.

The square root of 640346 is about 800.2162207804. The cubic root of 640346 is about 86.1929146869.

The spelling of 640346 in words is "six hundred forty thousand, three hundred forty-six".