646842 has 16 divisors (see below), whose sum is σ = 1478592. Its totient is φ = 184800.

The previous prime is 646837. The next prime is 646843. The reversal of 646842 is 248646.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 646842.

It is not an unprimeable number, because it can be changed into a prime (646843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7659 + ... + 7742.

It is an arithmetic number, because the mean of its divisors is an integer number (92412).

2⁶⁴⁶⁸⁴² is an apocalyptic number.

646842 is an abundant number, since it is smaller than the sum of its proper divisors (831750).

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

646842 is a wasteful number, since it uses less digits than its factorization.

646842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15413.

The product of its digits is 9216, while the sum is 30.

The square root of 646842 is about 804.2648817398. The cubic root of 646842 is about 86.4833964144.

The spelling of 646842 in words is "six hundred forty-six thousand, eight hundred forty-two".