1221313552 has 20 divisors (see below), whose sum is σ = 2367187900. Its totient is φ = 610426368.

The previous prime is 1221313493. The next prime is 1221313553. The reversal of 1221313552 is 2553131221.

It can be written as a sum of positive squares in 2 ways, for example, as 412252416 + 809061136 = 20304^2 + 28444^2 .

It is not an unprimeable number, because it can be changed into a prime (1221313553) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 34324 + ... + 60172.

It is an arithmetic number, because the mean of its divisors is an integer number (118359395).

Almost surely, 2^1221313552 is an apocalyptic number.

It is an amenable number.

1221313552 is a deficient number, since it is larger than the sum of its proper divisors (1145874348).

1221313552 is a wasteful number, since it uses less digits than its factorization.

1221313552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28810 (or 28804 counting only the distinct ones).

The product of its digits is 1800, while the sum is 25.

The square root of 1221313552 is about 34947.2967767179. The cubic root of 1221313552 is about 1068.9130814966.

Adding to 1221313552 its reverse (2553131221), we get a palindrome (3774444773).

The spelling of 1221313552 in words is "one billion, two hundred twenty-one million, three hundred thirteen thousand, five hundred fifty-two".