21543453542 has 16 divisors (see below), whose sum is σ = 34950333600. Its totient is φ = 9900455232.

The previous prime is 21543453511. The next prime is 21543453557. The reversal of 21543453542 is 24535434512.

It is a junction number, because it is equal to n+sod(n) for n = 21543453496 and 21543453505.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1772042 + ... + 1784157.

It is an arithmetic number, because the mean of its divisors is an integer number (2184395850).

Almost surely, 2^21543453542 is an apocalyptic number.

21543453542 is a deficient number, since it is larger than the sum of its proper divisors (13406880058).

21543453542 is a wasteful number, since it uses less digits than its factorization.

21543453542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3556447.

The product of its digits is 288000, while the sum is 38.

The spelling of 21543453542 in words is "twenty-one billion, five hundred forty-three million, four hundred fifty-three thousand, five hundred forty-two".