639113369 has 2 divisors, whose sum is σ = 639113370. Its totient is φ = 639113368.

The previous prime is 639113341. The next prime is 639113401. The reversal of 639113369 is 963311936.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 639078400 + 34969 = 25280^2 + 187^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-639113369 is a prime.

It is a super-2 number, since 2×639113369² = 816931796869060322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (639113569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319556684 + 319556685.

It is an arithmetic number, because the mean of its divisors is an integer number (319556685).

Almost surely, 2^639113369 is an apocalyptic number.

It is an amenable number.

639113369 is a deficient number, since it is larger than the sum of its proper divisors (1).

639113369 is an equidigital number, since it uses as much as digits as its factorization.

639113369 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 78732, while the sum is 41.

The square root of 639113369 is about 25280.6916242416. The cubic root of 639113369 is about 861.3757361454.

The spelling of 639113369 in words is "six hundred thirty-nine million, one hundred thirteen thousand, three hundred sixty-nine".