21316247543 has 4 divisors (see below), whose sum is σ = 21608251008. Its totient is φ = 21024244080.

The previous prime is 21316247531. The next prime is 21316247591. The reversal of 21316247543 is 34574261312.

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 21316247543 - 2⁸ = 21316247287 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21316247497 and 21316247506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21316247503) 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, 146001623 + ... + 146001768.

It is an arithmetic number, because the mean of its divisors is an integer number (5402062752).

Almost surely, 2^21316247543 is an apocalyptic number.

21316247543 is a deficient number, since it is larger than the sum of its proper divisors (292003465).

21316247543 is an equidigital number, since it uses as much as digits as its factorization.

21316247543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 292003464.

The product of its digits is 120960, while the sum is 38.

The spelling of 21316247543 in words is "twenty-one billion, three hundred sixteen million, two hundred forty-seven thousand, five hundred forty-three".