641804 has 12 divisors (see below), whose sum is σ = 1129128. Its totient is φ = 319200.

The previous prime is 641803. The next prime is 641813. The reversal of 641804 is 408146.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 641804.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 641804.

It is not an unprimeable number, because it can be changed into a prime (641803) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 839 + ... + 1409.

It is an arithmetic number, because the mean of its divisors is an integer number (94094).

2⁶⁴¹⁸⁰⁴ is an apocalyptic number.

It is an amenable number.

641804 is a deficient number, since it is larger than the sum of its proper divisors (487324).

641804 is a wasteful number, since it uses less digits than its factorization.

641804 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 856 (or 854 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 641804 is about 801.1267065827. The cubic root of 641804 is about 86.2582824784.

The spelling of 641804 in words is "six hundred forty-one thousand, eight hundred four".