20581975680 has 256 divisors, whose sum is σ = 76509792000. Its totient is φ = 4704301056.

The previous prime is 20581975643. The next prime is 20581975709. The reversal of 20581975680 is 8657918502.

It is a super-2 number, since 2×20581975680² (a number of 21 digits) contains 22 as substring.

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 31 ways as a sum of consecutive naturals, for example, 642934 + ... + 674186.

It is an arithmetic number, because the mean of its divisors is an integer number (298866375).

Almost surely, 2^20581975680 is an apocalyptic number.

20581975680 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 20581975680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38254896000).

20581975680 is an abundant number, since it is smaller than the sum of its proper divisors (55927816320).

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

20581975680 is an equidigital number, since it uses as much as digits as its factorization.

20581975680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31296 (or 31270 counting only the distinct ones).

The product of its (nonzero) digits is 1209600, while the sum is 51.

The spelling of 20581975680 in words is "twenty billion, five hundred eighty-one million, nine hundred seventy-five thousand, six hundred eighty".