640173663289 has 2 divisors, whose sum is σ = 640173663290. Its totient is φ = 640173663288.

The previous prime is 640173663277. The next prime is 640173663377. The reversal of 640173663289 is 982366371046.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 535702494889 + 104471168400 = 731917^2 + 323220^2 .

It is a cyclic number.

It is not a de Polignac number, because 640173663289 - 2⁷ = 640173663161 is a prime.

It is not a weakly prime, because it can be changed into another prime (640173663229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320086831644 + 320086831645.

It is an arithmetic number, because the mean of its divisors is an integer number (320086831645).

Almost surely, 2^640173663289 is an apocalyptic number.

It is an amenable number.

640173663289 is a deficient number, since it is larger than the sum of its proper divisors (1).

640173663289 is an equidigital number, since it uses as much as digits as its factorization.

640173663289 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7838208, while the sum is 55.

The spelling of 640173663289 in words is "six hundred forty billion, one hundred seventy-three million, six hundred sixty-three thousand, two hundred eighty-nine".