1221227756 has 12 divisors (see below), whose sum is σ = 2442455568. Its totient is φ = 523383312.

The previous prime is 1221227753. The next prime is 1221227771. The reversal of 1221227756 is 6577221221.

1221227756 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (1221227753) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21807611 + ... + 21807666.

It is an arithmetic number, because the mean of its divisors is an integer number (203537964).

Almost surely, 2^1221227756 is an apocalyptic number.

It is an amenable number.

1221227756 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

1221227756 is a wasteful number, since it uses less digits than its factorization.

1221227756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43615288 (or 43615286 counting only the distinct ones).

The product of its digits is 23520, while the sum is 35.

The square root of 1221227756 is about 34946.0692496309. The cubic root of 1221227756 is about 1068.8880509017. Note that the first 3 decimals are identical.

Adding to 1221227756 its reverse (6577221221), we get a palindrome (7798448977).

The spelling of 1221227756 in words is "one billion, two hundred twenty-one million, two hundred twenty-seven thousand, seven hundred fifty-six".