1221320044 has 12 divisors (see below), whose sum is σ = 2442640144. Its totient is φ = 523422864.

The previous prime is 1221320041. The next prime is 1221320047. The reversal of 1221320044 is 4400231221.

It is an interprime number because it is at equal distance from previous prime (1221320041) and next prime (1221320047).

1221320044 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (1221320041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21809259 + ... + 21809314.

Almost surely, 2^1221320044 is an apocalyptic number.

1221320044 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

1221320044 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.

1221320044 is a wasteful number, since it uses less digits than its factorization.

1221320044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43618584 (or 43618582 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 1221320044 is about 34947.3896593150. The cubic root of 1221320044 is about 1068.9149754605.

Adding to 1221320044 its reverse (4400231221), we get a palindrome (5621551265).

The spelling of 1221320044 in words is "one billion, two hundred twenty-one million, three hundred twenty thousand, forty-four".