21854085120 has 560 divisors, whose sum is σ = 89633621088. Its totient is φ = 4989911040.

The previous prime is 21854085109. The next prime is 21854085163. The reversal of 21854085120 is 2158045812.

21854085120 is a `hidden beast` number, since 2 + 18 + 540 + 85 + 1 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (560).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 23223850 + ... + 23224790.

Almost surely, 2^21854085120 is an apocalyptic number.

21854085120 is a gapful number since it is divisible by the number (20) 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 21854085120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44816810544).

21854085120 is an abundant number, since it is smaller than the sum of its proper divisors (67779535968).

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

21854085120 is an frugal number, since it uses more digits than its factorization.

21854085120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 991 (or 958 counting only the distinct ones).

The product of its (nonzero) digits is 25600, while the sum is 36.

It can be divided in two parts, 218540851 and 20, that added together give a triangular number (218540871 = T₂₀₉₀₆).

The spelling of 21854085120 in words is "twenty-one billion, eight hundred fifty-four million, eighty-five thousand, one hundred twenty".