21203240543 has 2 divisors, whose sum is σ = 21203240544. Its totient is φ = 21203240542.

The previous prime is 21203240537. The next prime is 21203240549. The reversal of 21203240543 is 34504230212.

It is a balanced prime because it is at equal distance from previous prime (21203240537) and next prime (21203240549).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21203240543 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21203240549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601620271 + 10601620272.

It is an arithmetic number, because the mean of its divisors is an integer number (10601620272).

Almost surely, 2^21203240543 is an apocalyptic number.

21203240543 is a deficient number, since it is larger than the sum of its proper divisors (1).

21203240543 is an equidigital number, since it uses as much as digits as its factorization.

21203240543 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5760, while the sum is 26.

Adding to 21203240543 its reverse (34504230212), we get a palindrome (55707470755).

The spelling of 21203240543 in words is "twenty-one billion, two hundred three million, two hundred forty thousand, five hundred forty-three".