642222 has 32 divisors (see below), whose sum is σ = 1632000. Its totient is φ = 183384.

The previous prime is 642217. The next prime is 642223. The reversal of 642222 is 222246.

It is a happy number.

642222 is a `hidden beast` number, since 642 + 2 + 22 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

642222 is a modest number, since divided by 2222 gives 64 as remainder.

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 642195 and 642204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642223) by changing a digit.

642222 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 15 ways as a sum of consecutive naturals, for example, 472 + ... + 1227.

It is an arithmetic number, because the mean of its divisors is an integer number (51000).

2⁶⁴²²²² is an apocalyptic number.

642222 is an abundant number, since it is smaller than the sum of its proper divisors (989778).

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

642222 is a wasteful number, since it uses less digits than its factorization.

642222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1717 (or 1711 counting only the distinct ones).

The product of its digits is 384, while the sum is 18.

The square root of 642222 is about 801.3875466964. The cubic root of 642222 is about 86.2770047765.

Adding to 642222 its reverse (222246), we get a palindrome (864468).

The spelling of 642222 in words is "six hundred forty-two thousand, two hundred twenty-two".