1223665 has 4 divisors (see below), whose sum is σ = 1468404. Its totient is φ = 978928.

The previous prime is 1223633. The next prime is 1223683. The reversal of 1223665 is 5663221.

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 531441 + 692224 = 729^2 + 832^2 .

It is a cyclic number.

It is not a de Polignac number, because 1223665 - 2⁵ = 1223633 is a prime.

It is an Ulam number.

It is a Duffinian number.

1223665 is a lucky number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 122362 + ... + 122371.

It is an arithmetic number, because the mean of its divisors is an integer number (367101).

2^1223665 is an apocalyptic number.

It is an amenable number.

1223665 is a deficient number, since it is larger than the sum of its proper divisors (244739).

1223665 is an equidigital number, since it uses as much as digits as its factorization.

1223665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244738.

The product of its digits is 2160, while the sum is 25.

The square root of 1223665 is about 1106.1939251325. The cubic root of 1223665 is about 106.9598649953.

Adding to 1223665 its reverse (5663221), we get a palindrome (6886886).

The spelling of 1223665 in words is "one million, two hundred twenty-three thousand, six hundred sixty-five".