1866665 has 8 divisors (see below), whose sum is σ = 2312448. Its totient is φ = 1445040.

The previous prime is 1866659. The next prime is 1866677. The reversal of 1866665 is 5666681.

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

It is not a de Polignac number, because 1866665 - 2⁴ = 1866649 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5867 + ... + 6176.

It is an arithmetic number, because the mean of its divisors is an integer number (289056).

2^1866665 is an apocalyptic number.

It is an amenable number.

1866665 is a deficient number, since it is larger than the sum of its proper divisors (445783).

1866665 is a wasteful number, since it uses less digits than its factorization.

1866665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12079.

The product of its digits is 51840, while the sum is 38.

The square root of 1866665 is about 1366.2594921903. The cubic root of 1866665 is about 123.1276133847.

The spelling of 1866665 in words is "one million, eight hundred sixty-six thousand, six hundred sixty-five".