128889617 has 2 divisors, whose sum is σ = 128889618. Its totient is φ = 128889616.

The previous prime is 128889589. The next prime is 128889641. The reversal of 128889617 is 716988821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 76457536 + 52432081 = 8744^2 + 7241^2 .

It is a cyclic number.

It is not a de Polignac number, because 128889617 - 2²⁰ = 127841041 is a prime.

It is a super-2 number, since 2×128889617² = 33225066740813378, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (128889647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64444808 + 64444809.

It is an arithmetic number, because the mean of its divisors is an integer number (64444809).

Almost surely, 2^128889617 is an apocalyptic number.

It is an amenable number.

128889617 is a deficient number, since it is larger than the sum of its proper divisors (1).

128889617 is an equidigital number, since it uses as much as digits as its factorization.

128889617 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 387072, while the sum is 50.

The square root of 128889617 is about 11352.9563110231. The cubic root of 128889617 is about 505.1332746306.

The spelling of 128889617 in words is "one hundred twenty-eight million, eight hundred eighty-nine thousand, six hundred seventeen".