128409469 has 4 divisors (see below), whose sum is σ = 128790844. Its totient is φ = 128028096.

The previous prime is 128409461. The next prime is 128409493. The reversal of 128409469 is 964904821.

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 53846244 + 74563225 = 7338^2 + 8635^2 .

It is a cyclic number.

It is not a de Polignac number, because 128409469 - 2³ = 128409461 is a prime.

It is a super-2 number, since 2×128409469² = 32977983457723922, 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 (128409461) 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, 190182 + ... + 190855.

It is an arithmetic number, because the mean of its divisors is an integer number (32197711).

Almost surely, 2^128409469 is an apocalyptic number.

It is an amenable number.

128409469 is a deficient number, since it is larger than the sum of its proper divisors (381375).

128409469 is an equidigital number, since it uses as much as digits as its factorization.

128409469 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 381374.

The product of its (nonzero) digits is 124416, while the sum is 43.

The square root of 128409469 is about 11331.7901939632. The cubic root of 128409469 is about 504.5052423247.

The spelling of 128409469 in words is "one hundred twenty-eight million, four hundred nine thousand, four hundred sixty-nine".