21543533405210 has 16 divisors (see below), whose sum is σ = 38778499866600. Its totient is φ = 8617382309376.

The previous prime is 21543533405209. The next prime is 21543533405297. The reversal of 21543533405210 is 1250433534512.

It can be written as a sum of positive squares in 4 ways, for example, as 5571625064041 + 15971908341169 = 2360429^2 + 3996487^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 855395 + ... + 6619574.

Almost surely, 2^{21543533405210} is an apocalyptic number.

21543533405210 is a deficient number, since it is larger than the sum of its proper divisors (17234966461390).

21543533405210 is a wasteful number, since it uses less digits than its factorization.

21543533405210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7763185.

The product of its (nonzero) digits is 216000, while the sum is 38.

Adding to 21543533405210 its reverse (1250433534512), we get a palindrome (22793966939722).

The spelling of 21543533405210 in words is "twenty-one trillion, five hundred forty-three billion, five hundred thirty-three million, four hundred five thousand, two hundred ten".