21525342543 has 8 divisors (see below), whose sum is σ = 31889396400. Its totient is φ = 14350228344.

The previous prime is 21525342529. The next prime is 21525342547. The reversal of 21525342543 is 34524352512.

21525342543 is a `hidden beast` number, since 21 + 5 + 2 + 53 + 42 + 543 = 666.

It is not a de Polignac number, because 21525342543 - 2⁹ = 21525342031 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21525342498 and 21525342507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21525342547) 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, 398617428 + ... + 398617481.

It is an arithmetic number, because the mean of its divisors is an integer number (3986174550).

Almost surely, 2^21525342543 is an apocalyptic number.

21525342543 is a deficient number, since it is larger than the sum of its proper divisors (10364053857).

21525342543 is an equidigital number, since it uses as much as digits as its factorization.

21525342543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 797234918 (or 797234912 counting only the distinct ones).

The product of its digits is 144000, while the sum is 36.

The spelling of 21525342543 in words is "twenty-one billion, five hundred twenty-five million, three hundred forty-two thousand, five hundred forty-three".