128731000 has 128 divisors (see below), whose sum is σ = 326851200. Its totient is φ = 47308800.

The previous prime is 128730997. The next prime is 128731013. The reversal of 128731000 is 137821.

It is a super-2 number, since 2×128731000² = 33143340722000000, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 666904 + ... + 667096.

It is an arithmetic number, because the mean of its divisors is an integer number (2553525).

Almost surely, 2^128731000 is an apocalyptic number.

128731000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128731000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (163425600).

128731000 is an abundant number, since it is smaller than the sum of its proper divisors (198120200).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

128731000 is a wasteful number, since it uses less digits than its factorization.

128731000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266 (or 252 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 22.

The square root of 128731000 is about 11345.9684469859. The cubic root of 128731000 is about 504.9259767984.

Adding to 128731000 its reverse (137821), we get a palindrome (128868821).

The spelling of 128731000 in words is "one hundred twenty-eight million, seven hundred thirty-one thousand".