642824 has 32 divisors (see below), whose sum is σ = 1485120. Its totient is φ = 254016.

The previous prime is 642809. The next prime is 642833. The reversal of 642824 is 428246.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a junction number, because it is equal to n+sod(n) for n = 642793 and 642802.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 642824.

It is an unprimeable number.

642824 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 7 ways as a sum of consecutive naturals, for example, 287 + ... + 1169.

It is an arithmetic number, because the mean of its divisors is an integer number (46410).

2⁶⁴²⁸²⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 642824, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (742560).

642824 is an abundant number, since it is smaller than the sum of its proper divisors (842296).

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

642824 is a wasteful number, since it uses less digits than its factorization.

642824 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 909 (or 905 counting only the distinct ones).

The product of its digits is 3072, while the sum is 26.

The square root of 642824 is about 801.7630572682. The cubic root of 642824 is about 86.3039541993.

The spelling of 642824 in words is "six hundred forty-two thousand, eight hundred twenty-four".