639950071 has 2 divisors, whose sum is σ = 639950072. Its totient is φ = 639950070.

The previous prime is 639950063. The next prime is 639950089. The reversal of 639950071 is 170059936.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 639950071 - 2³ = 639950063 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (639950041) 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, 319975035 + 319975036.

It is an arithmetic number, because the mean of its divisors is an integer number (319975036).

Almost surely, 2^639950071 is an apocalyptic number.

639950071 is a deficient number, since it is larger than the sum of its proper divisors (1).

639950071 is an equidigital number, since it uses as much as digits as its factorization.

639950071 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 51030, while the sum is 40.

The square root of 639950071 is about 25297.2344535920. The cubic root of 639950071 is about 861.7514652696.

The spelling of 639950071 in words is "six hundred thirty-nine million, nine hundred fifty thousand, seventy-one".