21351552543 has 48 divisors (see below), whose sum is σ = 33468664320. Its totient is φ = 13067488512.

The previous prime is 21351552437. The next prime is 21351552559. The reversal of 21351552543 is 34525515312.

21351552543 is a `hidden beast` number, since 2 + 1 + 3 + 51 + 552 + 54 + 3 = 666.

It is not a de Polignac number, because 21351552543 - 2¹⁶ = 21351487007 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21351552498 and 21351552507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21351557543) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 992580 + ... + 1013862.

It is an arithmetic number, because the mean of its divisors is an integer number (697263840).

Almost surely, 2^21351552543 is an apocalyptic number.

21351552543 is a deficient number, since it is larger than the sum of its proper divisors (12117111777).

21351552543 is a wasteful number, since it uses less digits than its factorization.

21351552543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21468 (or 21465 counting only the distinct ones).

The product of its digits is 90000, while the sum is 36.

The spelling of 21351552543 in words is "twenty-one billion, three hundred fifty-one million, five hundred fifty-two thousand, five hundred forty-three".