1665745 has 8 divisors (see below), whose sum is σ = 2116584. Its totient is φ = 1254144.

The previous prime is 1665709. The next prime is 1665757. The reversal of 1665745 is 5475661.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 266256 + 1399489 = 516^2 + 1183^2 .

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 1665745 - 2⁹ = 1665233 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1665745.

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, 9714 + ... + 9883.

It is an arithmetic number, because the mean of its divisors is an integer number (264573).

2^1665745 is an apocalyptic number.

It is an amenable number.

1665745 is a deficient number, since it is larger than the sum of its proper divisors (450839).

1665745 is a wasteful number, since it uses less digits than its factorization.

1665745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19619.

The product of its digits is 25200, while the sum is 34.

The square root of 1665745 is about 1290.6374394074. The cubic root of 1665745 is about 118.5412509865.

The spelling of 1665745 in words is "one million, six hundred sixty-five thousand, seven hundred forty-five".