128575491 has 16 divisors (see below), whose sum is σ = 187557120. Its totient is φ = 77700320.

The previous prime is 128575487. The next prime is 128575493. The reversal of 128575491 is 194575821.

It is a cyclic number.

It is not a de Polignac number, because 128575491 - 2² = 128575487 is a prime.

It is not an unprimeable number, because it can be changed into a prime (128575493) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6421 + ... + 17273.

It is an arithmetic number, because the mean of its divisors is an integer number (11722320).

Almost surely, 2^128575491 is an apocalyptic number.

128575491 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

128575491 is a deficient number, since it is larger than the sum of its proper divisors (58981629).

128575491 is a wasteful number, since it uses less digits than its factorization.

128575491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11226.

The product of its digits is 100800, while the sum is 42.

The square root of 128575491 is about 11339.1133251238. The cubic root of 128575491 is about 504.7225754603.

The spelling of 128575491 in words is "one hundred twenty-eight million, five hundred seventy-five thousand, four hundred ninety-one".