639086402489 has 2 divisors, whose sum is σ = 639086402490. Its totient is φ = 639086402488.

The previous prime is 639086402483. The next prime is 639086402491. The reversal of 639086402489 is 984204680936.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 523500002089 + 115586400400 = 723533^2 + 339980^2 .

It is a cyclic number.

It is not a de Polignac number, because 639086402489 - 2⁸ = 639086402233 is a prime.

Together with 639086402491, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (639086402483) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319543201244 + 319543201245.

It is an arithmetic number, because the mean of its divisors is an integer number (319543201245).

Almost surely, 2^639086402489 is an apocalyptic number.

It is an amenable number.

639086402489 is a deficient number, since it is larger than the sum of its proper divisors (1).

639086402489 is an equidigital number, since it uses as much as digits as its factorization.

639086402489 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17915904, while the sum is 59.

The spelling of 639086402489 in words is "six hundred thirty-nine billion, eighty-six million, four hundred two thousand, four hundred eighty-nine".