1221302543 has 2 divisors, whose sum is σ = 1221302544. Its totient is φ = 1221302542.

The previous prime is 1221302527. The next prime is 1221302561. The reversal of 1221302543 is 3452031221.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221302543 - 2⁴ = 1221302527 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221302513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610651271 + 610651272.

It is an arithmetic number, because the mean of its divisors is an integer number (610651272).

Almost surely, 2^1221302543 is an apocalyptic number.

1221302543 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221302543 is an equidigital number, since it uses as much as digits as its factorization.

1221302543 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 1221302543 is about 34947.1392677570. The cubic root of 1221302543 is about 1068.9098697362.

Adding to 1221302543 its reverse (3452031221), we get a palindrome (4673333764).

The spelling of 1221302543 in words is "one billion, two hundred twenty-one million, three hundred two thousand, five hundred forty-three".