641648 has 40 divisors (see below), whose sum is σ = 1508832. Its totient is φ = 258048.

The previous prime is 641639. The next prime is 641681. The reversal of 641648 is 846146.

It is a self number, because there is not a number n which added to its sum of digits gives 641648.

It is a congruent number.

It is an unprimeable number.

641648 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, 1736 + ... + 2072.

2⁶⁴¹⁶⁴⁸ is an apocalyptic number.

641648 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 641648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (754416).

641648 is an abundant number, since it is smaller than the sum of its proper divisors (867184).

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

641648 is a wasteful number, since it uses less digits than its factorization.

641648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 369 (or 363 counting only the distinct ones).

The product of its digits is 4608, while the sum is 29.

The square root of 641648 is about 801.0293377898. The cubic root of 641648 is about 86.2512931263.

The spelling of 641648 in words is "six hundred forty-one thousand, six hundred forty-eight".