1221304043 has 4 divisors (see below), whose sum is σ = 1221383880. Its totient is φ = 1221224208.

The previous prime is 1221304037. The next prime is 1221304067. The reversal of 1221304043 is 3404031221.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 3404031221 = 56099 ⋅60679.

It is a cyclic number.

It is not a de Polignac number, because 1221304043 - 2²⁶ = 1154195179 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221304033) 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, 8978 + ... + 50231.

It is an arithmetic number, because the mean of its divisors is an integer number (305345970).

Almost surely, 2^1221304043 is an apocalyptic number.

1221304043 is a deficient number, since it is larger than the sum of its proper divisors (79837).

1221304043 is an equidigital number, since it uses as much as digits as its factorization.

1221304043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79836.

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 1221304043 is about 34947.1607287345. The cubic root of 1221304043 is about 1068.9103073466.

Adding to 1221304043 its reverse (3404031221), we get a palindrome (4625335264).

The spelling of 1221304043 in words is "one billion, two hundred twenty-one million, three hundred four thousand, forty-three".