128542 has 4 divisors (see below), whose sum is σ = 192816. Its totient is φ = 64270.

The previous prime is 128521. The next prime is 128549. The reversal of 128542 is 245821.

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

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32134 + ... + 32137.

It is an arithmetic number, because the mean of its divisors is an integer number (48204).

2¹²⁸⁵⁴² is an apocalyptic number.

128542 is a deficient number, since it is larger than the sum of its proper divisors (64274).

128542 is an equidigital number, since it uses as much as digits as its factorization.

It is an anagram of its base 9 representation: 128542 = (215284)₉.

128542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64273.

The product of its digits is 640, while the sum is 22.

The square root of 128542 is about 358.5275442696. The cubic root of 128542 is about 50.4678748726.

The spelling of 128542 in words is "one hundred twenty-eight thousand, five hundred forty-two".