2161816 has 32 divisors (see below), whose sum is σ = 4377600. Its totient is φ = 997920.

The previous prime is 2161813. The next prime is 2161823. The reversal of 2161816 is 6181612.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161813) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5515 + ... + 5893.

It is an arithmetic number, because the mean of its divisors is an integer number (136800).

2^2161816 is an apocalyptic number.

It is an amenable number.

2161816 is an abundant number, since it is smaller than the sum of its proper divisors (2215784).

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

2161816 is a wasteful number, since it uses less digits than its factorization.

2161816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 439 (or 435 counting only the distinct ones).

The product of its digits is 576, while the sum is 25.

The square root of 2161816 is about 1470.3115316150. The cubic root of 2161816 is about 129.3022976747.

The spelling of 2161816 in words is "two million, one hundred sixty-one thousand, eight hundred sixteen".