2165898 has 48 divisors (see below), whose sum is σ = 5171040. Its totient is φ = 602784.

The previous prime is 2165897. The next prime is 2165903. The reversal of 2165898 is 8985612.

It is a super-2 number, since 2×2165898² = 9382228292808, which contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (2165893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15513 + ... + 15651.

It is an arithmetic number, because the mean of its divisors is an integer number (107730).

2^2165898 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2165898, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2585520).

2165898 is an abundant number, since it is smaller than the sum of its proper divisors (3005142).

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

2165898 is a wasteful number, since it uses less digits than its factorization.

2165898 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211 (or 204 counting only the distinct ones).

The product of its digits is 34560, while the sum is 39.

The square root of 2165898 is about 1471.6990181420. The cubic root of 2165898 is about 129.3836305475.

The spelling of 2165898 in words is "two million, one hundred sixty-five thousand, eight hundred ninety-eight".