20563387520 has 128 divisors (see below), whose sum is σ = 53667638640. Its totient is φ = 7488405504.

The previous prime is 20563387441. The next prime is 20563387577. The reversal of 20563387520 is 2578336502.

It can be written as a sum of positive squares in 8 ways, for example, as 13417052224 + 7146335296 = 115832^2 + 84536^2 .

It is a tau number, because it is divible by the number of its divisors (128).

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 590432 + ... + 624288.

Almost surely, 2^20563387520 is an apocalyptic number.

20563387520 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 20563387520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26833819320).

20563387520 is an abundant number, since it is smaller than the sum of its proper divisors (33104251120).

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

20563387520 is a wasteful number, since it uses less digits than its factorization.

20563387520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33962 (or 33950 counting only the distinct ones).

The product of its (nonzero) digits is 302400, while the sum is 41.

The spelling of 20563387520 in words is "twenty billion, five hundred sixty-three million, three hundred eighty-seven thousand, five hundred twenty".