1643461543 has 2 divisors, whose sum is σ = 1643461544. Its totient is φ = 1643461542.

The previous prime is 1643461531. The next prime is 1643461583. The reversal of 1643461543 is 3451643461.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1643461543 - 2¹³ = 1643453351 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1643461583) 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, 821730771 + 821730772.

It is an arithmetic number, because the mean of its divisors is an integer number (821730772).

Almost surely, 2^1643461543 is an apocalyptic number.

1643461543 is a deficient number, since it is larger than the sum of its proper divisors (1).

1643461543 is an equidigital number, since it uses as much as digits as its factorization.

1643461543 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 103680, while the sum is 37.

The square root of 1643461543 is about 40539.6292903623. The cubic root of 1643461543 is about 1180.1028214051.

It can be divided in two parts, 16434 and 61543, that added together give a palindrome (77977).

The spelling of 1643461543 in words is "one billion, six hundred forty-three million, four hundred sixty-one thousand, five hundred forty-three".