20865943854 has 96 divisors (see below), whose sum is σ = 54752495616. Its totient is φ = 5606380800.

The previous prime is 20865943753. The next prime is 20865943859. The reversal of 20865943854 is 45834956802.

20865943854 is a `hidden beast` number, since 208 + 6 + 59 + 4 + 385 + 4 = 666.

It is a super-2 number, since 2×20865943854² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20865943854.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20865943859) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3181879 + ... + 3188429.

It is an arithmetic number, because the mean of its divisors is an integer number (570338496).

Almost surely, 2^20865943854 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20865943854, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27376247808).

20865943854 is an abundant number, since it is smaller than the sum of its proper divisors (33886551762).

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

20865943854 is a wasteful number, since it uses less digits than its factorization.

20865943854 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8070 (or 8067 counting only the distinct ones).

The product of its (nonzero) digits is 8294400, while the sum is 54.

The spelling of 20865943854 in words is "twenty billion, eight hundred sixty-five million, nine hundred forty-three thousand, eight hundred fifty-four".