1221777944 has 16 divisors (see below), whose sum is σ = 2291596920. Its totient is φ = 610685440.

The previous prime is 1221777937. The next prime is 1221777971. The reversal of 1221777944 is 4497771221.

It is a junction number, because it is equal to n+sod(n) for n = 1221777895 and 1221777904.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1784 + ... + 49464.

Almost surely, 2^1221777944 is an apocalyptic number.

It is an amenable number.

1221777944 is a deficient number, since it is larger than the sum of its proper divisors (1069818976).

1221777944 is a wasteful number, since it uses less digits than its factorization.

1221777944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50890 (or 50886 counting only the distinct ones).

The product of its digits is 197568, while the sum is 44.

The square root of 1221777944 is about 34953.9403215145. The cubic root of 1221777944 is about 1069.0485454212.

The spelling of 1221777944 in words is "one billion, two hundred twenty-one million, seven hundred seventy-seven thousand, nine hundred forty-four".