21531432555543 has 16 divisors (see below), whose sum is σ = 30291677539200. Its totient is φ = 13566344124960.

The previous prime is 21531432555517. The next prime is 21531432555557. The reversal of 21531432555543 is 34555523413512.

It is not a de Polignac number, because 21531432555543 - 2¹⁰ = 21531432554519 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21531432555492 and 21531432555501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21531432554543) 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, 450745128 + ... + 450792893.

It is an arithmetic number, because the mean of its divisors is an integer number (1893229846200).

Almost surely, 2^{21531432555543} is an apocalyptic number.

21531432555543 is a deficient number, since it is larger than the sum of its proper divisors (8760244983657).

21531432555543 is a wasteful number, since it uses less digits than its factorization.

21531432555543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 901538462.

The product of its digits is 5400000, while the sum is 48.

The spelling of 21531432555543 in words is "twenty-one trillion, five hundred thirty-one billion, four hundred thirty-two million, five hundred fifty-five thousand, five hundred forty-three".