128738717 has 2 divisors, whose sum is σ = 128738718. Its totient is φ = 128738716.

The previous prime is 128738713. The next prime is 128738719. The reversal of 128738717 is 717837821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80658361 + 48080356 = 8981^2 + 6934^2 .

It is an emirp because it is prime and its reverse (717837821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 128738717 - 2² = 128738713 is a prime.

Together with 128738719, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128738713) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64369358 + 64369359.

It is an arithmetic number, because the mean of its divisors is an integer number (64369359).

Almost surely, 2^128738717 is an apocalyptic number.

It is an amenable number.

128738717 is a deficient number, since it is larger than the sum of its proper divisors (1).

128738717 is an equidigital number, since it uses as much as digits as its factorization.

128738717 is an evil number, because the sum of its binary digits is even.

The product of its digits is 131712, while the sum is 44.

The square root of 128738717 is about 11346.3085186328. The cubic root of 128738717 is about 504.9360661473.

It can be divided in two parts, 1287 and 38717, that added together give a palindrome (40004).

The spelling of 128738717 in words is "one hundred twenty-eight million, seven hundred thirty-eight thousand, seven hundred seventeen".