1223645 has 16 divisors (see below), whose sum is σ = 1548288. Its totient is φ = 927360.

The previous prime is 1223633. The next prime is 1223683. The reversal of 1223645 is 5463221.

It is not a de Polignac number, because 1223645 - 2¹² = 1219549 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 1223645.

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 15 ways as a sum of consecutive naturals, for example, 9572 + ... + 9698.

It is an arithmetic number, because the mean of its divisors is an integer number (96768).

2^1223645 is an apocalyptic number.

It is an amenable number.

1223645 is a deficient number, since it is larger than the sum of its proper divisors (324643).

1223645 is a wasteful number, since it uses less digits than its factorization.

1223645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220.

The product of its digits is 1440, while the sum is 23.

The square root of 1223645 is about 1106.1848850893. The cubic root of 1223645 is about 106.9592822625.

Adding to 1223645 its reverse (5463221), we get a palindrome (6686866).

The spelling of 1223645 in words is "one million, two hundred twenty-three thousand, six hundred forty-five".