21543743233 has 2 divisors, whose sum is σ = 21543743234. Its totient is φ = 21543743232.

The previous prime is 21543743231. The next prime is 21543743251. The reversal of 21543743233 is 33234734512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21213339904 + 330403329 = 145648^2 + 18177^2 .

It is a cyclic number.

It is not a de Polignac number, because 21543743233 - 2¹ = 21543743231 is a prime.

Together with 21543743231, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 21543743192 and 21543743201.

It is not a weakly prime, because it can be changed into another prime (21543743231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10771871616 + 10771871617.

It is an arithmetic number, because the mean of its divisors is an integer number (10771871617).

Almost surely, 2^21543743233 is an apocalyptic number.

It is an amenable number.

21543743233 is a deficient number, since it is larger than the sum of its proper divisors (1).

21543743233 is an equidigital number, since it uses as much as digits as its factorization.

21543743233 is an evil number, because the sum of its binary digits is even.

The product of its digits is 181440, while the sum is 37.

The spelling of 21543743233 in words is "twenty-one billion, five hundred forty-three million, seven hundred forty-three thousand, two hundred thirty-three".