640306317 has 16 divisors (see below), whose sum is σ = 986670720. Its totient is φ = 361777152.

The previous prime is 640306279. The next prime is 640306319. The reversal of 640306317 is 713603046.

It is not a de Polignac number, because 640306317 - 2⁷ = 640306189 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640306319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 169428 + ... + 173165.

It is an arithmetic number, because the mean of its divisors is an integer number (61666920).

Almost surely, 2^640306317 is an apocalyptic number.

It is an amenable number.

640306317 is a deficient number, since it is larger than the sum of its proper divisors (346364403).

640306317 is a wasteful number, since it uses less digits than its factorization.

640306317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 342692.

The product of its (nonzero) digits is 9072, while the sum is 30.

The square root of 640306317 is about 25304.2746784017. The cubic root of 640306317 is about 861.9113415778.

The spelling of 640306317 in words is "six hundred forty million, three hundred six thousand, three hundred seventeen".