128540 has 12 divisors (see below), whose sum is σ = 269976. Its totient is φ = 51408.

The previous prime is 128521. The next prime is 128549. The reversal of 128540 is 45821.

128540 = 36² + 37² + ... + 75².

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 6427 = 128540 / (1 + 2 + 8 + 5 + 4 + 0).

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128549) by changing a digit.

128540 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3194 + ... + 3233.

It is an arithmetic number, because the mean of its divisors is an integer number (22498).

2¹²⁸⁵⁴⁰ is an apocalyptic number.

128540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

128540 is an abundant number, since it is smaller than the sum of its proper divisors (141436).

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

128540 is a wasteful number, since it uses less digits than its factorization.

128540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6436 (or 6434 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 128540 is about 358.5247550728. The cubic root of 128540 is about 50.4676131261.

The spelling of 128540 in words is "one hundred twenty-eight thousand, five hundred forty".