640368 has 30 divisors (see below), whose sum is σ = 1792544. Its totient is φ = 213408.

The previous prime is 640363. The next prime is 640369. The reversal of 640368 is 863046.

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 640368.

It is not an unprimeable number, because it can be changed into a prime (640363) by changing a digit.

640368 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 5 ways as a sum of consecutive naturals, for example, 2080 + ... + 2367.

2⁶⁴⁰³⁶⁸ is an apocalyptic number.

It is an amenable number.

640368 is an abundant number, since it is smaller than the sum of its proper divisors (1152176).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640368 is a wasteful number, since it uses less digits than its factorization.

640368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4461 (or 4452 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 640368 is about 800.2299669470. The cubic root of 640368 is about 86.1939017691.

The spelling of 640368 in words is "six hundred forty thousand, three hundred sixty-eight".