128642 has 8 divisors (see below), whose sum is σ = 194832. Its totient is φ = 63700.

The previous prime is 128629. The next prime is 128657. The reversal of 128642 is 246821.

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17 + ... + 507.

It is an arithmetic number, because the mean of its divisors is an integer number (24354).

2¹²⁸⁶⁴² is an apocalyptic number.

128642 is a deficient number, since it is larger than the sum of its proper divisors (66190).

128642 is a wasteful number, since it uses less digits than its factorization.

128642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 624.

The product of its digits is 768, while the sum is 23.

The square root of 128642 is about 358.6669764559. Note that the first 3 decimals coincide. The cubic root of 128642 is about 50.4809587397.

The spelling of 128642 in words is "one hundred twenty-eight thousand, six hundred forty-two".