20517316544 has 56 divisors (see below), whose sum is σ = 41180430720. Its totient is φ = 10141496064.

The previous prime is 20517316531. The next prime is 20517316559. The reversal of 20517316544 is 44561371502.

It is a super-2 number, since 2×20517316544² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20517316498 and 20517316507.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4341767 + ... + 4346489.

Almost surely, 2^20517316544 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 20517316544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20590215360).

20517316544 is an abundant number, since it is smaller than the sum of its proper divisors (20663114176).

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

20517316544 is a wasteful number, since it uses less digits than its factorization.

20517316544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5497 (or 5487 counting only the distinct ones).

The product of its (nonzero) digits is 100800, while the sum is 38.

The spelling of 20517316544 in words is "twenty billion, five hundred seventeen million, three hundred sixteen thousand, five hundred forty-four".