1220555 has 16 divisors (see below), whose sum is σ = 1714944. Its totient is φ = 816480.

The previous prime is 1220507. The next prime is 1220591. The reversal of 1220555 is 5550221.

It is not a de Polignac number, because 1220555 - 2⁶ = 1220491 is a prime.

It is an Ulam 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, 1100 + ... + 1910.

It is an arithmetic number, because the mean of its divisors is an integer number (107184).

2^1220555 is an apocalyptic number.

1220555 is a deficient number, since it is larger than the sum of its proper divisors (494389).

1220555 is an equidigital number, since it uses as much as digits as its factorization.

1220555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 866.

The product of its (nonzero) digits is 500, while the sum is 20.

The square root of 1220555 is about 1104.7873098475. The cubic root of 1220555 is about 106.8691736732.

Adding to 1220555 its reverse (5550221), we get a palindrome (6770776).

The spelling of 1220555 in words is "one million, two hundred twenty thousand, five hundred fifty-five".