2161805184 has 192 divisors, whose sum is σ = 7756145280. Its totient is φ = 561484800.

The previous prime is 2161805117. The next prime is 2161805189. The reversal of 2161805184 is 4815081612.

2161805184 is a `hidden beast` number, since 2 + 1 + 61 + 80 + 518 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (192).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161805189) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 76519 + ... + 100889.

It is an arithmetic number, because the mean of its divisors is an integer number (40396590).

Almost surely, 2^2161805184 is an apocalyptic number.

2161805184 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 2161805184, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3878072640).

2161805184 is an abundant number, since it is smaller than the sum of its proper divisors (5594340096).

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

2161805184 is a wasteful number, since it uses less digits than its factorization.

2161805184 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24409 (or 24394 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 36.

The square root of 2161805184 is about 46495.2167862459. The cubic root of 2161805184 is about 1293.0208203250.

Adding to 2161805184 its reverse (4815081612), we get a palindrome (6976886796).

The spelling of 2161805184 in words is "two billion, one hundred sixty-one million, eight hundred five thousand, one hundred eighty-four".