21355435052543 has 16 divisors (see below), whose sum is σ = 21962089559424. Its totient is φ = 20750336870400.

The previous prime is 21355435052533. The next prime is 21355435052563. The reversal of 21355435052543 is 34525053455312.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21355435052543 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21355435052533) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 424645946 + ... + 424696232.

It is an arithmetic number, because the mean of its divisors is an integer number (1372630597464).

Almost surely, 2^{21355435052543} is an apocalyptic number.

21355435052543 is a deficient number, since it is larger than the sum of its proper divisors (606654506881).

21355435052543 is a wasteful number, since it uses less digits than its factorization.

21355435052543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65522.

The product of its (nonzero) digits is 5400000, while the sum is 47.

The spelling of 21355435052543 in words is "twenty-one trillion, three hundred fifty-five billion, four hundred thirty-five million, fifty-two thousand, five hundred forty-three".