639166703389 has 2 divisors, whose sum is σ = 639166703390. Its totient is φ = 639166703388.

The previous prime is 639166703339. The next prime is 639166703393. The reversal of 639166703389 is 983307661936.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 521471736900 + 117694966489 = 722130^2 + 343067^2 .

It is a cyclic number.

It is not a de Polignac number, because 639166703389 - 2¹⁹ = 639166179101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (639166703339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319583351694 + 319583351695.

It is an arithmetic number, because the mean of its divisors is an integer number (319583351695).

Almost surely, 2^639166703389 is an apocalyptic number.

It is an amenable number.

639166703389 is a deficient number, since it is larger than the sum of its proper divisors (1).

639166703389 is an equidigital number, since it uses as much as digits as its factorization.

639166703389 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 26453952, while the sum is 61.

The spelling of 639166703389 in words is "six hundred thirty-nine billion, one hundred sixty-six million, seven hundred three thousand, three hundred eighty-nine".