642858 has 16 divisors (see below), whose sum is σ = 1293600. Its totient is φ = 212976.

The previous prime is 642853. The next prime is 642869. The reversal of 642858 is 858246.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (642853) 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 in 7 ways as a sum of consecutive naturals, for example, 1668 + ... + 2016.

It is an arithmetic number, because the mean of its divisors is an integer number (80850).

2⁶⁴²⁸⁵⁸ is an apocalyptic number.

642858 is an abundant number, since it is smaller than the sum of its proper divisors (650742).

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

642858 is a wasteful number, since it uses less digits than its factorization.

642858 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 661.

The product of its digits is 15360, while the sum is 33.

The square root of 642858 is about 801.7842602596. The cubic root of 642858 is about 86.3054757577.

The spelling of 642858 in words is "six hundred forty-two thousand, eight hundred fifty-eight".