1221311144 has 16 divisors (see below), whose sum is σ = 2424662100. Its totient is φ = 574734592.

The previous prime is 1221311111. The next prime is 1221311149. The reversal of 1221311144 is 4411131221.

It can be written as a sum of positive squares in 2 ways, for example, as 1066806244 + 154504900 = 32662^2 + 12430^2 .

It is not an unprimeable number, because it can be changed into a prime (1221311149) 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, 4489979 + ... + 4490250.

Almost surely, 2^1221311144 is an apocalyptic number.

It is an amenable number.

1221311144 is a deficient number, since it is larger than the sum of its proper divisors (1203350956).

1221311144 is a wasteful number, since it uses less digits than its factorization.

1221311144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8980252 (or 8980248 counting only the distinct ones).

The product of its digits is 192, while the sum is 20.

The square root of 1221311144 is about 34947.2623248231. The cubic root of 1221311144 is about 1068.9123789895.

Adding to 1221311144 its reverse (4411131221), we get a palindrome (5632442365).

The spelling of 1221311144 in words is "one billion, two hundred twenty-one million, three hundred eleven thousand, one hundred forty-four".