20858020517664 has 1440 divisors, whose sum is σ = 74085548866560. Its totient is φ = 5701106073600.

The previous prime is 20858020517599. The next prime is 20858020517707. The reversal of 20858020517664 is 46671502085802.

20858020517664 is a `hidden beast` number, since 2 + 0 + 8 + 580 + 2 + 0 + 51 + 7 + 6 + 6 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 20858020517664.

It is an unprimeable number.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 45641182524 + ... + 45641182980.

It is an arithmetic number, because the mean of its divisors is an integer number (51448297824).

Almost surely, 2^{20858020517664} is an apocalyptic number.

20858020517664 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 20858020517664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37042774433280).

20858020517664 is an abundant number, since it is smaller than the sum of its proper divisors (53227528348896).

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

20858020517664 is a wasteful number, since it uses less digits than its factorization.

20858020517664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 744 (or 710 counting only the distinct ones).

The product of its (nonzero) digits is 6451200, while the sum is 54.

The spelling of 20858020517664 in words is "twenty trillion, eight hundred fifty-eight billion, twenty million, five hundred seventeen thousand, six hundred sixty-four".