21550243543 has 8 divisors (see below), whose sum is σ = 21789648000. Its totient is φ = 21312103008.

The previous prime is 21550243513. The next prime is 21550243571. The reversal of 21550243543 is 34534205512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21550243543 - 2¹⁷ = 21550112471 is a prime.

It is a super-2 number, since 2×21550243543² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21550243499 and 21550243508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21550243513) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 281671 + ... + 349912.

It is an arithmetic number, because the mean of its divisors is an integer number (2723706000).

Almost surely, 2^21550243543 is an apocalyptic number.

21550243543 is a deficient number, since it is larger than the sum of its proper divisors (239404457).

21550243543 is a wasteful number, since it uses less digits than its factorization.

21550243543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 631961.

The product of its (nonzero) digits is 72000, while the sum is 34.

The spelling of 21550243543 in words is "twenty-one billion, five hundred fifty million, two hundred forty-three thousand, five hundred forty-three".