21118947548 has 12 divisors (see below), whose sum is σ = 36982435560. Its totient is φ = 10552537392.

The previous prime is 21118947491. The next prime is 21118947593. The reversal of 21118947548 is 84574981112.

It is a junction number, because it is equal to n+sod(n) for n = 21118947496 and 21118947505.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1727243 + ... + 1739426.

It is an arithmetic number, because the mean of its divisors is an integer number (3081869630).

Almost surely, 2^21118947548 is an apocalyptic number.

It is an amenable number.

21118947548 is a deficient number, since it is larger than the sum of its proper divisors (15863488012).

21118947548 is a wasteful number, since it uses less digits than its factorization.

21118947548 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3468196 (or 3468194 counting only the distinct ones).

The product of its digits is 645120, while the sum is 50.

The spelling of 21118947548 in words is "twenty-one billion, one hundred eighteen million, nine hundred forty-seven thousand, five hundred forty-eight".