641984 has 28 divisors (see below), whose sum is σ = 1456944. Its totient is φ = 274944.

The previous prime is 641981. The next prime is 642011. The reversal of 641984 is 489146.

It is a tau number, because it is divible by the number of its divisors (28).

It is a Harshad number since it is a multiple of its sum of digits (32).

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 641984.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641981) 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, 269 + ... + 1164.

2⁶⁴¹⁹⁸⁴ is an apocalyptic number.

641984 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

641984 is an abundant number, since it is smaller than the sum of its proper divisors (814960).

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

641984 is a wasteful number, since it uses less digits than its factorization.

641984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1452 (or 1442 counting only the distinct ones).

The product of its digits is 6912, while the sum is 32.

The square root of 641984 is about 801.2390404867. The cubic root of 641984 is about 86.2663457083.

It can be divided in two parts, 64 and 1984, that added together give a 11-th power (2048 = 2¹¹).

The spelling of 641984 in words is "six hundred forty-one thousand, nine hundred eighty-four".