1220256 has 72 divisors (see below), whose sum is σ = 3669120. Its totient is φ = 383616.

The previous prime is 1220251. The next prime is 1220257. The reversal of 1220256 is 6520221.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (1220251) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5361 + ... + 5583.

It is an arithmetic number, because the mean of its divisors is an integer number (50960).

2^1220256 is an apocalyptic number.

1220256 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1220256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1834560).

1220256 is an abundant number, since it is smaller than the sum of its proper divisors (2448864).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1220256 is a wasteful number, since it uses less digits than its factorization.

1220256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 258 (or 247 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 1220256 is about 1104.6519813950. The cubic root of 1220256 is about 106.8604463613.

Adding to 1220256 its reverse (6520221), we get a palindrome (7740477).

The spelling of 1220256 in words is "one million, two hundred twenty thousand, two hundred fifty-six".