20641328560 has 80 divisors (see below), whose sum is σ = 49145961600. Its totient is φ = 8060203008.

The previous prime is 20641328551. The next prime is 20641328567. The reversal of 20641328560 is 6582314602.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-3 number, since 3×20641328560³ (a number of 32 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (20641328567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 544132 + ... + 580828.

It is an arithmetic number, because the mean of its divisors is an integer number (614324520).

Almost surely, 2^20641328560 is an apocalyptic number.

20641328560 is a gapful number since it is divisible by the number (20) 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 20641328560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24572980800).

20641328560 is an abundant number, since it is smaller than the sum of its proper divisors (28504633040).

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

20641328560 is a wasteful number, since it uses less digits than its factorization.

20641328560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36878 (or 36872 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 37.

The spelling of 20641328560 in words is "twenty billion, six hundred forty-one million, three hundred twenty-eight thousand, five hundred sixty".