1221108256 has 24 divisors (see below), whose sum is σ = 2404892700. Its totient is φ = 610341888.

The previous prime is 1221108227. The next prime is 1221108271. The reversal of 1221108256 is 6528011221.

It can be written as a sum of positive squares in 2 ways, for example, as 1032979600 + 188128656 = 32140^2 + 13716^2 .

It is a super-2 number, since 2×1221108256² = 2982210745742723072, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 130420 + ... + 139468.

Almost surely, 2^1221108256 is an apocalyptic number.

1221108256 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1221108256 is a deficient number, since it is larger than the sum of its proper divisors (1183784444).

1221108256 is an equidigital number, since it uses as much as digits as its factorization.

1221108256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13276 (or 13268 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 1221108256 is about 34944.3594303859. The cubic root of 1221108256 is about 1068.8531853636.

Adding to 1221108256 its reverse (6528011221), we get a palindrome (7749119477).

The spelling of 1221108256 in words is "one billion, two hundred twenty-one million, one hundred eight thousand, two hundred fifty-six".