2166385 has 8 divisors (see below), whose sum is σ = 2799720. Its totient is φ = 1599744.

The previous prime is 2166319. The next prime is 2166403. The reversal of 2166385 is 5836612.

2166385 = T₂₂₅ + T₂₂₆ + ... + T₂₈₉.

It can be written as a sum of positive squares in 4 ways, for example, as 112896 + 2053489 = 336^2 + 1433^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2166385 - 2⁹ = 2165873 is a prime.

It is an Ulam number.

2166385 is a lucky number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16600 + ... + 16729.

It is an arithmetic number, because the mean of its divisors is an integer number (349965).

2^2166385 is an apocalyptic number.

It is an amenable number.

2166385 is a deficient number, since it is larger than the sum of its proper divisors (633335).

2166385 is a wasteful number, since it uses less digits than its factorization.

2166385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33347.

The product of its digits is 8640, while the sum is 31.

The square root of 2166385 is about 1471.8644638689. The cubic root of 2166385 is about 129.3933270808.

The spelling of 2166385 in words is "two million, one hundred sixty-six thousand, three hundred eighty-five".