75128409 has 12 divisors (see below), whose sum is σ = 108718896. Its totient is φ = 49993272.

The previous prime is 75128399. The next prime is 75128411. The reversal of 75128409 is 90482157.

It is not a de Polignac number, because 75128409 - 2¹⁹ = 74604121 is a prime.

It is not an unprimeable number, because it can be changed into a prime (75128479) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2347 + ... + 12480.

It is an arithmetic number, because the mean of its divisors is an integer number (9059908).

Almost surely, 2^75128409 is an apocalyptic number.

It is an amenable number.

75128409 is a deficient number, since it is larger than the sum of its proper divisors (33590487).

75128409 is a wasteful number, since it uses less digits than its factorization.

75128409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15396 (or 15393 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 75128409 is about 8667.6645643449. The cubic root of 75128409 is about 421.9568717483.

The spelling of 75128409 in words is "seventy-five million, one hundred twenty-eight thousand, four hundred nine".