1221344443 has 4 divisors (see below), whose sum is σ = 1332375768. Its totient is φ = 1110313120.

The previous prime is 1221344431. The next prime is 1221344477. The reversal of 1221344443 is 3444431221.

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

It is a cyclic number.

It is not a de Polignac number, because 1221344443 - 2⁹ = 1221343931 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221344543) 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, 55515646 + ... + 55515667.

It is an arithmetic number, because the mean of its divisors is an integer number (333093942).

Almost surely, 2^1221344443 is an apocalyptic number.

1221344443 is a deficient number, since it is larger than the sum of its proper divisors (111031325).

1221344443 is a wasteful number, since it uses less digits than its factorization.

1221344443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111031324.

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

The square root of 1221344443 is about 34947.7387394378. The cubic root of 1221344443 is about 1068.9220935191.

Adding to 1221344443 its reverse (3444431221), we get a palindrome (4665775664).

The spelling of 1221344443 in words is "one billion, two hundred twenty-one million, three hundred forty-four thousand, four hundred forty-three".