128689673 has 4 divisors (see below), whose sum is σ = 147073920. Its totient is φ = 110305428.

The previous prime is 128689667. The next prime is 128689681. The reversal of 128689673 is 376986821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 376986821 = 37 ⋅10188833.

It is a cyclic number.

It is not a de Polignac number, because 128689673 - 2¹⁸ = 128427529 is a prime.

It is a super-2 number, since 2×128689673² = 33122063873693858, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (128689073) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9192113 + ... + 9192126.

It is an arithmetic number, because the mean of its divisors is an integer number (36768480).

Almost surely, 2^128689673 is an apocalyptic number.

It is an amenable number.

128689673 is a deficient number, since it is larger than the sum of its proper divisors (18384247).

128689673 is an equidigital number, since it uses as much as digits as its factorization.

128689673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18384246.

The product of its digits is 870912, while the sum is 50.

The square root of 128689673 is about 11344.1470812045. The cubic root of 128689673 is about 504.8719382497.

The spelling of 128689673 in words is "one hundred twenty-eight million, six hundred eighty-nine thousand, six hundred seventy-three".