128818817 has 2 divisors, whose sum is σ = 128818818. Its totient is φ = 128818816.

The previous prime is 128818787. The next prime is 128818819. The reversal of 128818817 is 718818821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 99181681 + 29637136 = 9959^2 + 5444^2 .

It is a cyclic number.

It is not a de Polignac number, because 128818817 - 2²⁰ = 127770241 is a prime.

It is a super-2 number, since 2×128818817² = 33188575226558978, which contains 22 as substring.

Together with 128818819, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (128818819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64409408 + 64409409.

It is an arithmetic number, because the mean of its divisors is an integer number (64409409).

Almost surely, 2^128818817 is an apocalyptic number.

It is an amenable number.

128818817 is a deficient number, since it is larger than the sum of its proper divisors (1).

128818817 is an equidigital number, since it uses as much as digits as its factorization.

128818817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 57344, while the sum is 44.

The square root of 128818817 is about 11349.8377521443. The cubic root of 128818817 is about 505.0407665682.

The spelling of 128818817 in words is "one hundred twenty-eight million, eight hundred eighteen thousand, eight hundred seventeen".