1221065056 has 12 divisors (see below), whose sum is σ = 2403971892. Its totient is φ = 610532512.

The previous prime is 1221065047. The next prime is 1221065057. The reversal of 1221065056 is 6505601221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221065057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19079110 + ... + 19079173.

It is an arithmetic number, because the mean of its divisors is an integer number (200330991).

Almost surely, 2^1221065056 is an apocalyptic number.

1221065056 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1221065056 is a deficient number, since it is larger than the sum of its proper divisors (1182906836).

1221065056 is an equidigital number, since it uses as much as digits as its factorization.

1221065056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38158293 (or 38158285 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 1221065056 is about 34943.7412994087. The cubic root of 1221065056 is about 1068.8405806929.

Adding to 1221065056 its reverse (6505601221), we get a palindrome (7726666277).

The spelling of 1221065056 in words is "one billion, two hundred twenty-one million, sixty-five thousand, fifty-six".