1023665 has 4 divisors (see below), whose sum is σ = 1228404. Its totient is φ = 818928.

The previous prime is 1023653. The next prime is 1023697. The reversal of 1023665 is 5663201.

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 190096 + 833569 = 436^2 + 913^2 .

It is a cyclic number.

It is not a de Polignac number, because 1023665 - 2⁶ = 1023601 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 1023665.

It is a congruent 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 3 ways as a sum of consecutive naturals, for example, 102362 + ... + 102371.

It is an arithmetic number, because the mean of its divisors is an integer number (307101).

2^1023665 is an apocalyptic number.

It is an amenable number.

1023665 is a deficient number, since it is larger than the sum of its proper divisors (204739).

1023665 is an equidigital number, since it uses as much as digits as its factorization.

1023665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204738.

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 1023665 is about 1011.7633122425. The cubic root of 1023665 is about 100.7826912940.

Adding to 1023665 its reverse (5663201), we get a palindrome (6686866).

It can be divided in two parts, 10236 and 65, that added together give a palindrome (10301).

The spelling of 1023665 in words is "one million, twenty-three thousand, six hundred sixty-five".