1220305 has 8 divisors (see below), whose sum is σ = 1488744. Its totient is φ = 960000.

The previous prime is 1220257. The next prime is 1220309. The reversal of 1220305 is 5030221.

It can be written as a sum of positive squares in 4 ways, for example, as 88209 + 1132096 = 297^2 + 1064^2 .

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

It is not a de Polignac number, because 1220305 - 2⁹ = 1219793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1220309) by changing a digit.

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, 1696 + ... + 2305.

It is an arithmetic number, because the mean of its divisors is an integer number (186093).

2^1220305 is an apocalyptic number.

It is an amenable number.

1220305 is a deficient number, since it is larger than the sum of its proper divisors (268439).

1220305 is an equidigital number, since it uses as much as digits as its factorization.

1220305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4067.

The product of its (nonzero) digits is 60, while the sum is 13.

The square root of 1220305 is about 1104.6741601033. The cubic root of 1220305 is about 106.8618766874.

Adding to 1220305 its reverse (5030221), we get a palindrome (6250526).

It can be divided in two parts, 1220 and 305, that multiplied together give a square (372100 = 610²).

The spelling of 1220305 in words is "one million, two hundred twenty thousand, three hundred five".