1205431342421 has 2 divisors, whose sum is σ = 1205431342422. Its totient is φ = 1205431342420.

The previous prime is 1205431342393. The next prime is 1205431342457. The reversal of 1205431342421 is 1242431345021.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1103730943396 + 101700399025 = 1050586^2 + 318905^2 .

It is an emirp because it is prime and its reverse (1242431345021) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1205431342421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1205431342481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 602715671210 + 602715671211.

It is an arithmetic number, because the mean of its divisors is an integer number (602715671211).

Almost surely, 2^{1205431342421} is an apocalyptic number.

It is an amenable number.

1205431342421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1205431342421 is an equidigital number, since it uses as much as digits as its factorization.

1205431342421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23040, while the sum is 32.

Adding to 1205431342421 its reverse (1242431345021), we get a palindrome (2447862687442).

The spelling of 1205431342421 in words is "one trillion, two hundred five billion, four hundred thirty-one million, three hundred forty-two thousand, four hundred twenty-one".