639118522369 has 2 divisors, whose sum is σ = 639118522370. Its totient is φ = 639118522368.

The previous prime is 639118522319. The next prime is 639118522379. The reversal of 639118522369 is 963225811936.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 470579536144 + 168538986225 = 685988^2 + 410535^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-639118522369 is a prime.

It is a super-2 number, since 2×639118522369² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (639118522319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319559261184 + 319559261185.

It is an arithmetic number, because the mean of its divisors is an integer number (319559261185).

Almost surely, 2^639118522369 is an apocalyptic number.

It is an amenable number.

639118522369 is a deficient number, since it is larger than the sum of its proper divisors (1).

639118522369 is an equidigital number, since it uses as much as digits as its factorization.

639118522369 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4199040, while the sum is 55.

The spelling of 639118522369 in words is "six hundred thirty-nine billion, one hundred eighteen million, five hundred twenty-two thousand, three hundred sixty-nine".