20845719856 has 60 divisors (see below), whose sum is σ = 44944165056. Its totient is φ = 9310654080.

The previous prime is 20845719847. The next prime is 20845719859. The reversal of 20845719856 is 65891754802.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 20845719797 and 20845719806.

It is not an unprimeable number, because it can be changed into a prime (20845719859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 147745 + ... + 252031.

Almost surely, 2^20845719856 is an apocalyptic number.

20845719856 is a gapful number since it is divisible by the number (26) 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 20845719856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22472082528).

20845719856 is an abundant number, since it is smaller than the sum of its proper divisors (24098445200).

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

20845719856 is a wasteful number, since it uses less digits than its factorization.

20845719856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104370 (or 104333 counting only the distinct ones).

The product of its (nonzero) digits is 4838400, while the sum is 55.

The spelling of 20845719856 in words is "twenty billion, eight hundred forty-five million, seven hundred nineteen thousand, eight hundred fifty-six".