128817427 has 2 divisors, whose sum is σ = 128817428. Its totient is φ = 128817426.

The previous prime is 128817371. The next prime is 128817439. The reversal of 128817427 is 724718821.

It is a strong prime.

It is an emirp because it is prime and its reverse (724718821) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128817427 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 128817427.

It is not a weakly prime, because it can be changed into another prime (128817487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64408713 + 64408714.

It is an arithmetic number, because the mean of its divisors is an integer number (64408714).

Almost surely, 2^128817427 is an apocalyptic number.

128817427 is a deficient number, since it is larger than the sum of its proper divisors (1).

128817427 is an equidigital number, since it uses as much as digits as its factorization.

128817427 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 50176, while the sum is 40.

The square root of 128817427 is about 11349.7765176236. The cubic root of 128817427 is about 505.0389500396.

The spelling of 128817427 in words is "one hundred twenty-eight million, eight hundred seventeen thousand, four hundred twenty-seven".