1221366944 has 36 divisors (see below), whose sum is σ = 2797151994. Its totient is φ = 523442304.

The previous prime is 1221366931. The next prime is 1221366961. The reversal of 1221366944 is 4496631221.

It can be written as a sum of positive squares in only one way, i.e., 1082410000 + 138956944 = 32900^2 + 11788^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1221366898 and 1221366907.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 387899 + ... + 391034.

Almost surely, 2^1221366944 is an apocalyptic number.

1221366944 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

1221366944 is an abundant number, since it is smaller than the sum of its proper divisors (1575785050).

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

1221366944 is an equidigital number, since it uses as much as digits as its factorization.

1221366944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 778957 (or 778942 counting only the distinct ones).

The product of its digits is 62208, while the sum is 38.

The square root of 1221366944 is about 34948.0606615017. The cubic root of 1221366944 is about 1068.9286577793.

The spelling of 1221366944 in words is "one billion, two hundred twenty-one million, three hundred sixty-six thousand, nine hundred forty-four".