639784575389 has 2 divisors, whose sum is σ = 639784575390. Its totient is φ = 639784575388.

The previous prime is 639784575377. The next prime is 639784575461. The reversal of 639784575389 is 983575487936.

639784575389 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 527235732100 + 112548843289 = 726110^2 + 335483^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-639784575389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (639784575289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319892287694 + 319892287695.

It is an arithmetic number, because the mean of its divisors is an integer number (319892287695).

Almost surely, 2^639784575389 is an apocalyptic number.

It is an amenable number.

639784575389 is a deficient number, since it is larger than the sum of its proper divisors (1).

639784575389 is an equidigital number, since it uses as much as digits as its factorization.

639784575389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1371686400, while the sum is 74.

The spelling of 639784575389 in words is "six hundred thirty-nine billion, seven hundred eighty-four million, five hundred seventy-five thousand, three hundred eighty-nine".