21544142543 has 32 divisors (see below), whose sum is σ = 27810639360. Its totient is φ = 16194648960.

The previous prime is 21544142539. The next prime is 21544142549. The reversal of 21544142543 is 34524144512.

It is a happy number.

It is not a de Polignac number, because 21544142543 - 2² = 21544142539 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21544142549) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3062396 + ... + 3069422.

It is an arithmetic number, because the mean of its divisors is an integer number (869082480).

Almost surely, 2^21544142543 is an apocalyptic number.

21544142543 is a deficient number, since it is larger than the sum of its proper divisors (6266496817).

21544142543 is a wasteful number, since it uses less digits than its factorization.

21544142543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8447.

The product of its digits is 76800, while the sum is 35.

The spelling of 21544142543 in words is "twenty-one billion, five hundred forty-four million, one hundred forty-two thousand, five hundred forty-three".