128169669 has 4 divisors (see below), whose sum is σ = 170892896. Its totient is φ = 85446444.

The previous prime is 128169641. The next prime is 128169673. The reversal of 128169669 is 966961821.

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.

It is not a de Polignac number, because 128169669 - 2⁵ = 128169637 is a prime.

It is a super-2 number, since 2×128169669² = 32854928103139122, 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 (128169169) 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, 21361609 + ... + 21361614.

It is an arithmetic number, because the mean of its divisors is an integer number (42723224).

Almost surely, 2^128169669 is an apocalyptic number.

It is an amenable number.

128169669 is a deficient number, since it is larger than the sum of its proper divisors (42723227).

128169669 is an equidigital number, since it uses as much as digits as its factorization.

128169669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42723226.

The product of its digits is 279936, while the sum is 48.

The square root of 128169669 is about 11321.2043970595. The cubic root of 128169669 is about 504.1909982505.

The spelling of 128169669 in words is "one hundred twenty-eight million, one hundred sixty-nine thousand, six hundred sixty-nine".