2166389 has 4 divisors (see below), whose sum is σ = 2178540. Its totient is φ = 2154240.

The previous prime is 2166319. The next prime is 2166403. The reversal of 2166389 is 9836612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 87025 + 2079364 = 295^2 + 1442^2 .

It is a cyclic number.

It is not a de Polignac number, because 2166389 - 2²⁰ = 1117813 is a prime.

It is a d-powerful number, because it can be written as 2²¹ + 1 + 6³ + 6⁵ + 3⁷ + 8 + 9⁵ .

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2166319) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5804 + ... + 6165.

It is an arithmetic number, because the mean of its divisors is an integer number (544635).

2^2166389 is an apocalyptic number.

It is an amenable number.

2166389 is a deficient number, since it is larger than the sum of its proper divisors (12151).

2166389 is a wasteful number, since it uses less digits than its factorization.

2166389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12150.

The product of its digits is 15552, while the sum is 35.

The square root of 2166389 is about 1471.8658226890. The cubic root of 2166389 is about 129.3934067177.

The spelling of 2166389 in words is "two million, one hundred sixty-six thousand, three hundred eighty-nine".