640307 has 2 divisors, whose sum is σ = 640308. Its totient is φ = 640306.

The previous prime is 640303. The next prime is 640333. The reversal of 640307 is 703046.

640307 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 640307 - 2² = 640303 is a prime.

It is a Chen prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 640307.

It is not a weakly prime, because it can be changed into another prime (640303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320153 + 320154.

It is an arithmetic number, because the mean of its divisors is an integer number (320154).

2⁶⁴⁰³⁰⁷ is an apocalyptic number.

640307 is a deficient number, since it is larger than the sum of its proper divisors (1).

640307 is an equidigital number, since it uses as much as digits as its factorization.

640307 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 504, while the sum is 20.

The square root of 640307 is about 800.1918519955. The cubic root of 640307 is about 86.1911648038.

The spelling of 640307 in words is "six hundred forty thousand, three hundred seven".