639547313 has 2 divisors, whose sum is σ = 639547314. Its totient is φ = 639547312.

The previous prime is 639547297. The next prime is 639547333. The reversal of 639547313 is 313745936.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 430687009 + 208860304 = 20753^2 + 14452^2 .

It is a cyclic number.

It is not a de Polignac number, because 639547313 - 2⁴ = 639547297 is a prime.

It is not a weakly prime, because it can be changed into another prime (639547333) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319773656 + 319773657.

It is an arithmetic number, because the mean of its divisors is an integer number (319773657).

Almost surely, 2^639547313 is an apocalyptic number.

It is an amenable number.

639547313 is a deficient number, since it is larger than the sum of its proper divisors (1).

639547313 is an equidigital number, since it uses as much as digits as its factorization.

639547313 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 204120, while the sum is 41.

The square root of 639547313 is about 25289.2726862597. The cubic root of 639547313 is about 861.5706438015.

The spelling of 639547313 in words is "six hundred thirty-nine million, five hundred forty-seven thousand, three hundred thirteen".