1221255 has 24 divisors (see below), whose sum is σ = 2419872. Its totient is φ = 558144.

The previous prime is 1221251. The next prime is 1221289. The reversal of 1221255 is 5521221.

It is not a de Polignac number, because 1221255 - 2² = 1221251 is a prime.

1221255 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221251) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1624 + ... + 2253.

It is an arithmetic number, because the mean of its divisors is an integer number (100828).

2^1221255 is an apocalyptic number.

1221255 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1221255 is a deficient number, since it is larger than the sum of its proper divisors (1198617).

1221255 is a wasteful number, since it uses less digits than its factorization.

1221255 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3895 (or 3892 counting only the distinct ones).

The product of its digits is 200, while the sum is 18.

The square root of 1221255 is about 1105.1040674977. The cubic root of 1221255 is about 106.8895999342.

Adding to 1221255 its reverse (5521221), we get a palindrome (6742476).

The spelling of 1221255 in words is "one million, two hundred twenty-one thousand, two hundred fifty-five".