641221568 has 56 divisors (see below), whose sum is σ = 1373440992. Its totient is φ = 295271424.

The previous prime is 641221549. The next prime is 641221579. The reversal of 641221568 is 865122146.

It is a super-2 number, since 2×641221568² = 822330198536757248, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 662621 + ... + 663587.

It is an arithmetic number, because the mean of its divisors is an integer number (24525732).

Almost surely, 2^641221568 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 641221568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (686720496).

641221568 is an abundant number, since it is smaller than the sum of its proper divisors (732219424).

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

641221568 is a wasteful number, since it uses less digits than its factorization.

641221568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1789 (or 1779 counting only the distinct ones).

The product of its digits is 23040, while the sum is 35.

The square root of 641221568 is about 25322.3531292019. The cubic root of 641221568 is about 862.3218168080.

The spelling of 641221568 in words is "six hundred forty-one million, two hundred twenty-one thousand, five hundred sixty-eight".