2185217856 has 168 divisors, whose sum is σ = 6570293184. Its totient is φ = 693073920.

The previous prime is 2185217813. The next prime is 2185217857. The reversal of 2185217856 is 6587125812.

2185217856 is a `hidden beast` number, since 2 + 1 + 8 + 521 + 78 + 56 = 666.

Its product of digits (268800) is a multiple of the sum of its prime divisors (896).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2185217857) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3722395 + ... + 3722981.

It is an arithmetic number, because the mean of its divisors is an integer number (39108888).

Almost surely, 2^2185217856 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 2185217856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3285146592).

2185217856 is an abundant number, since it is smaller than the sum of its proper divisors (4385075328).

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

2185217856 is a wasteful number, since it uses less digits than its factorization.

2185217856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 909 (or 896 counting only the distinct ones).

The product of its digits is 268800, while the sum is 45.

The square root of 2185217856 is about 46746.3138225893. The cubic root of 2185217856 is about 1297.6719390797.

The spelling of 2185217856 in words is "two billion, one hundred eighty-five million, two hundred seventeen thousand, eight hundred fifty-six".