1660865 has 8 divisors (see below), whose sum is σ = 2000808. Its totient is φ = 1323520.

The previous prime is 1660843. The next prime is 1660871. The reversal of 1660865 is 5680661.

It can be written as a sum of positive squares in 4 ways, for example, as 179776 + 1481089 = 424^2 + 1217^2 .

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

It is not a de Polignac number, because 1660865 - 2⁸ = 1660609 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 (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1295 + ... + 2235.

It is an arithmetic number, because the mean of its divisors is an integer number (250101).

2^1660865 is an apocalyptic number.

It is an amenable number.

1660865 is a deficient number, since it is larger than the sum of its proper divisors (339943).

1660865 is an equidigital number, since it uses as much as digits as its factorization.

1660865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1299.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 1660865 is about 1288.7455140562. The cubic root of 1660865 is about 118.4253774812.

The spelling of 1660865 in words is "one million, six hundred sixty thousand, eight hundred sixty-five".