21543644132 has 24 divisors (see below), whose sum is σ = 37777084800. Its totient is φ = 10750215456.

The previous prime is 21543644131. The next prime is 21543644137. The reversal of 21543644132 is 23144634512.

It is a junction number, because it is equal to n+sod(n) for n = 21543644092 and 21543644101.

It is not an unprimeable number, because it can be changed into a prime (21543644131) 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, 6905669 + ... + 6908787.

It is an arithmetic number, because the mean of its divisors is an integer number (1574045200).

Almost surely, 2^21543644132 is an apocalyptic number.

It is an amenable number.

21543644132 is a deficient number, since it is larger than the sum of its proper divisors (16233440668).

21543644132 is a wasteful number, since it uses less digits than its factorization.

21543644132 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6035 (or 6033 counting only the distinct ones).

The product of its digits is 69120, while the sum is 35.

The spelling of 21543644132 in words is "twenty-one billion, five hundred forty-three million, six hundred forty-four thousand, one hundred thirty-two".