20017929943872 has 1344 divisors, whose sum is σ = 73437206480640. Its totient is φ = 5312758284288.

The previous prime is 20017929943871. The next prime is 20017929943901. The reversal of 20017929943872 is 27834992971002.

20017929943872 is a `hidden beast` number, since 2 + 0 + 0 + 179 + 29 + 9 + 438 + 7 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (1344).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20017929943871) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 63955047588 + ... + 63955047900.

Almost surely, 2^{20017929943872} 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 20017929943872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36718603240320).

20017929943872 is an abundant number, since it is smaller than the sum of its proper divisors (53419276536768).

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

20017929943872 is a wasteful number, since it uses less digits than its factorization.

20017929943872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 805 (or 782 counting only the distinct ones).

The product of its (nonzero) digits is 27433728, while the sum is 63.

The spelling of 20017929943872 in words is "twenty trillion, seventeen billion, nine hundred twenty-nine million, nine hundred forty-three thousand, eight hundred seventy-two".