128318669 has 4 divisors (see below), whose sum is σ = 135866844. Its totient is φ = 120770496.

The previous prime is 128318657. The next prime is 128318689. The reversal of 128318669 is 966813821.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 104796169 + 23522500 = 10237^2 + 4850^2 .

It is a cyclic number.

It is not a de Polignac number, because 128318669 - 2¹² = 128314573 is a prime.

It is a super-2 number, since 2×128318669² = 32931361627863122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128318629) 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, 3774062 + ... + 3774095.

It is an arithmetic number, because the mean of its divisors is an integer number (33966711).

Almost surely, 2^128318669 is an apocalyptic number.

It is an amenable number.

128318669 is a deficient number, since it is larger than the sum of its proper divisors (7548175).

128318669 is an equidigital number, since it uses as much as digits as its factorization.

128318669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7548174.

The product of its digits is 124416, while the sum is 44.

The square root of 128318669 is about 11327.7830575978. The cubic root of 128318669 is about 504.3863002197.

The spelling of 128318669 in words is "one hundred twenty-eight million, three hundred eighteen thousand, six hundred sixty-nine".