2161904136 has 128 divisors (see below), whose sum is σ = 6475161600. Its totient is φ = 588107520.

The previous prime is 2161904099. The next prime is 2161904141. The reversal of 2161904136 is 6314091612.

It is a junction number, because it is equal to n+sod(n) for n = 2161904097 and 2161904106.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 922326 + ... + 924666.

It is an arithmetic number, because the mean of its divisors is an integer number (50587200).

Almost surely, 2^2161904136 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 2161904136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3237580800).

2161904136 is an abundant number, since it is smaller than the sum of its proper divisors (4313257464).

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

2161904136 is a wasteful number, since it uses less digits than its factorization.

2161904136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2619 (or 2615 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 33.

The square root of 2161904136 is about 46496.2808835287. The cubic root of 2161904136 is about 1293.0405484431.

Adding to 2161904136 its reverse (6314091612), we get a palindrome (8475995748).

The spelling of 2161904136 in words is "two billion, one hundred sixty-one million, nine hundred four thousand, one hundred thirty-six".