640005313 has 2 divisors, whose sum is σ = 640005314. Its totient is φ = 640005312.

The previous prime is 640005299. The next prime is 640005343. The reversal of 640005313 is 313500046.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 520387344 + 119617969 = 22812^2 + 10937^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640005313 is a prime.

It is not a weakly prime, because it can be changed into another prime (640005343) 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 as a sum of consecutive naturals, namely, 320002656 + 320002657.

It is an arithmetic number, because the mean of its divisors is an integer number (320002657).

Almost surely, 2^640005313 is an apocalyptic number.

It is an amenable number.

640005313 is a deficient number, since it is larger than the sum of its proper divisors (1).

640005313 is an equidigital number, since it uses as much as digits as its factorization.

640005313 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080, while the sum is 22.

The square root of 640005313 is about 25298.3262885117. The cubic root of 640005313 is about 861.7762606961.

Adding to 640005313 its reverse (313500046), we get a palindrome (953505359).

The spelling of 640005313 in words is "six hundred forty million, five thousand, three hundred thirteen".