128669285 has 4 divisors (see below), whose sum is σ = 154403148. Its totient is φ = 102935424.

The previous prime is 128669263. The next prime is 128669297. The reversal of 128669285 is 582966821.

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 29008996 + 99660289 = 5386^2 + 9983^2 .

It is a cyclic number.

It is not a de Polignac number, because 128669285 - 2²⁴ = 111892069 is a prime.

It is a super-2 number, since 2×128669285² = 33111569804822450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12866924 + ... + 12866933.

It is an arithmetic number, because the mean of its divisors is an integer number (38600787).

Almost surely, 2^128669285 is an apocalyptic number.

It is an amenable number.

128669285 is a deficient number, since it is larger than the sum of its proper divisors (25733863).

128669285 is an equidigital number, since it uses as much as digits as its factorization.

128669285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25733862.

The product of its digits is 414720, while the sum is 47.

The square root of 128669285 is about 11343.2484324377. The cubic root of 128669285 is about 504.8452749532.

The spelling of 128669285 in words is "one hundred twenty-eight million, six hundred sixty-nine thousand, two hundred eighty-five".