128731587 has 8 divisors (see below), whose sum is σ = 171789840. Its totient is φ = 85747200.

The previous prime is 128731571. The next prime is 128731613. The reversal of 128731587 is 785137821.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 128731587 - 2⁴ = 128731571 is a prime.

It is not an unprimeable number, because it can be changed into a prime (128731487) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14262 + ... + 21467.

It is an arithmetic number, because the mean of its divisors is an integer number (21473730).

Almost surely, 2^128731587 is an apocalyptic number.

128731587 is a deficient number, since it is larger than the sum of its proper divisors (43058253).

128731587 is a wasteful number, since it uses less digits than its factorization.

128731587 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36933.

The product of its digits is 94080, while the sum is 42.

The square root of 128731587 is about 11345.9943151757. The cubic root of 128731587 is about 504.9267442673.

The spelling of 128731587 in words is "one hundred twenty-eight million, seven hundred thirty-one thousand, five hundred eighty-seven".