20856306168 has 128 divisors (see below), whose sum is σ = 59360716800. Its totient is φ = 6781356288.

The previous prime is 20856306131. The next prime is 20856306169. The reversal of 20856306168 is 86160365802.

20856306168 is a `hidden beast` number, since 2 + 0 + 8 + 5 + 630 + 6 + 1 + 6 + 8 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20856306169) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13308921 + ... + 13310487.

It is an arithmetic number, because the mean of its divisors is an integer number (463755600).

Almost surely, 2^20856306168 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 20856306168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29680358400).

20856306168 is an abundant number, since it is smaller than the sum of its proper divisors (38504410632).

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

20856306168 is a wasteful number, since it uses less digits than its factorization.

20856306168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3058 (or 3048 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 45.

The spelling of 20856306168 in words is "twenty billion, eight hundred fifty-six million, three hundred six thousand, one hundred sixty-eight".