641904 has 40 divisors (see below), whose sum is σ = 1702272. Its totient is φ = 208320.

The previous prime is 641897. The next prime is 641909. The reversal of 641904 is 409146.

641904 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641909) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1909 + ... + 2219.

2⁶⁴¹⁹⁰⁴ 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 641904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (851136).

641904 is an abundant number, since it is smaller than the sum of its proper divisors (1060368).

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

641904 is a wasteful number, since it uses less digits than its factorization.

641904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 365 (or 359 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 641904 is about 801.1891162516. The cubic root of 641904 is about 86.2627622367.

The spelling of 641904 in words is "six hundred forty-one thousand, nine hundred four".