21203340543 has 32 divisors (see below), whose sum is σ = 39163461120. Its totient is φ = 11014721280.

The previous prime is 21203340481. The next prime is 21203340547. The reversal of 21203340543 is 34504330212.

21203340543 is a `hidden beast` number, since 212 + 0 + 3 + 3 + 405 + 43 = 666.

It is not a de Polignac number, because 21203340543 - 2⁶ = 21203340479 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21203340547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5097330 + ... + 5101487.

It is an arithmetic number, because the mean of its divisors is an integer number (1223858160).

Almost surely, 2^21203340543 is an apocalyptic number.

21203340543 is a deficient number, since it is larger than the sum of its proper divisors (17960120577).

21203340543 is a wasteful number, since it uses less digits than its factorization.

21203340543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10198844 (or 10198838 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 27.

Adding to 21203340543 its reverse (34504330212), we get a palindrome (55707670755).

The spelling of 21203340543 in words is "twenty-one billion, two hundred three million, three hundred forty thousand, five hundred forty-three".