21202553543 has 4 divisors (see below), whose sum is σ = 21266609928. Its totient is φ = 21138497160.

The previous prime is 21202553513. The next prime is 21202553551. The reversal of 21202553543 is 34535520212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21202553543 - 2⁸ = 21202553287 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 (21202553513) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32027696 + ... + 32028357.

It is an arithmetic number, because the mean of its divisors is an integer number (5316652482).

Almost surely, 2^21202553543 is an apocalyptic number.

21202553543 is a deficient number, since it is larger than the sum of its proper divisors (64056385).

21202553543 is an equidigital number, since it uses as much as digits as its factorization.

21202553543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64056384.

The product of its (nonzero) digits is 36000, while the sum is 32.

The spelling of 21202553543 in words is "twenty-one billion, two hundred two million, five hundred fifty-three thousand, five hundred forty-three".