128599491 has 4 divisors (see below), whose sum is σ = 171465992. Its totient is φ = 85732992.

The previous prime is 128599483. The next prime is 128599547. The reversal of 128599491 is 194995821.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 128599491 - 2³ = 128599483 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 128599491.

It is not an unprimeable number, because it can be changed into a prime (128599421) 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, 21433246 + ... + 21433251.

It is an arithmetic number, because the mean of its divisors is an integer number (42866498).

Almost surely, 2^128599491 is an apocalyptic number.

128599491 is a deficient number, since it is larger than the sum of its proper divisors (42866501).

128599491 is an equidigital number, since it uses as much as digits as its factorization.

128599491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42866500.

The product of its digits is 233280, while the sum is 48.

The square root of 128599491 is about 11340.1715595488. The cubic root of 128599491 is about 504.7539774746.

The spelling of 128599491 in words is "one hundred twenty-eight million, five hundred ninety-nine thousand, four hundred ninety-one".