1221342043 has 4 divisors (see below), whose sum is σ = 1221448248. Its totient is φ = 1221235840.

The previous prime is 1221342037. The next prime is 1221342077. The reversal of 1221342043 is 3402431221.

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.

It is a cyclic number.

It is not a de Polignac number, because 1221342043 - 2⁵ = 1221342011 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221348043) 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, 33421 + ... + 59662.

It is an arithmetic number, because the mean of its divisors is an integer number (305362062).

Almost surely, 2^1221342043 is an apocalyptic number.

1221342043 is a deficient number, since it is larger than the sum of its proper divisors (106205).

1221342043 is an equidigital number, since it uses as much as digits as its factorization.

1221342043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106204.

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 1221342043 is about 34947.7044024354. The cubic root of 1221342043 is about 1068.9213933577.

Adding to 1221342043 its reverse (3402431221), we get a palindrome (4623773264).

The spelling of 1221342043 in words is "one billion, two hundred twenty-one million, three hundred forty-two thousand, forty-three".