1213444243 has 4 divisors (see below), whose sum is σ = 1323757368. Its totient is φ = 1103131120.

The previous prime is 1213444237. The next prime is 1213444247. The reversal of 1213444243 is 3424443121.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1213444243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1213444247) by changing a digit.

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, 55156546 + ... + 55156567.

It is an arithmetic number, because the mean of its divisors is an integer number (330939342).

Almost surely, 2^1213444243 is an apocalyptic number.

1213444243 is a deficient number, since it is larger than the sum of its proper divisors (110313125).

1213444243 is a wasteful number, since it uses less digits than its factorization.

1213444243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110313124.

The product of its digits is 9216, while the sum is 28.

The square root of 1213444243 is about 34834.5265935968. The cubic root of 1213444243 is about 1066.6123514118.

Adding to 1213444243 its reverse (3424443121), we get a palindrome (4637887364).

The spelling of 1213444243 in words is "one billion, two hundred thirteen million, four hundred forty-four thousand, two hundred forty-three".