642822 has 8 divisors (see below), whose sum is σ = 1285656. Its totient is φ = 214272.

The previous prime is 642809. The next prime is 642833. The reversal of 642822 is 228246.

642822 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

642822 is an admirable number.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 642792 and 642801.

It is a congruent number.

It is an unprimeable number.

642822 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, 53563 + ... + 53574.

It is an arithmetic number, because the mean of its divisors is an integer number (160707).

2⁶⁴²⁸²² is an apocalyptic number.

642822 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

642822 is a wasteful number, since it uses less digits than its factorization.

642822 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107142.

The product of its digits is 1536, while the sum is 24.

The square root of 642822 is about 801.7618100159. The cubic root of 642822 is about 86.3038646942.

The spelling of 642822 in words is "six hundred forty-two thousand, eight hundred twenty-two".