20117189664 has 576 divisors, whose sum is σ = 72384399360. Its totient is φ = 5208053760.

The previous prime is 20117189647. The next prime is 20117189681. The reversal of 20117189664 is 46698171102.

It is an interprime number because it is at equal distance from previous prime (20117189647) and next prime (20117189681).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 36777039 + ... + 36777585.

It is an arithmetic number, because the mean of its divisors is an integer number (125667360).

Almost surely, 2^20117189664 is an apocalyptic number.

20117189664 is a gapful number since it is divisible by the number (24) 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 20117189664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36192199680).

20117189664 is an abundant number, since it is smaller than the sum of its proper divisors (52267209696).

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

20117189664 is a wasteful number, since it uses less digits than its factorization.

20117189664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 653 (or 642 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The spelling of 20117189664 in words is "twenty billion, one hundred seventeen million, one hundred eighty-nine thousand, six hundred sixty-four".