640319507 has 12 divisors (see below), whose sum is σ = 673923120. Its totient is φ = 607665072.

The previous prime is 640319473. The next prime is 640319527. The reversal of 640319507 is 705913046.

It is a de Polignac number, because none of the positive numbers 2^k-640319507 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640319527) 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, 97778 + ... + 104120.

It is an arithmetic number, because the mean of its divisors is an integer number (56160260).

Almost surely, 2^640319507 is an apocalyptic number.

640319507 is a deficient number, since it is larger than the sum of its proper divisors (33603613).

640319507 is an equidigital number, since it uses as much as digits as its factorization.

640319507 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6490 (or 6431 counting only the distinct ones).

The product of its (nonzero) digits is 22680, while the sum is 35.

The square root of 640319507 is about 25304.5353049607. The cubic root of 640319507 is about 861.9172598558.

The spelling of 640319507 in words is "six hundred forty million, three hundred nineteen thousand, five hundred seven".