21043112005 has 8 divisors (see below), whose sum is σ = 25433402400. Its totient is φ = 16713377616.

The previous prime is 21043111987. The next prime is 21043112011. The reversal of 21043112005 is 50021134012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21043112005 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15138235 + ... + 15139624.

It is an arithmetic number, because the mean of its divisors is an integer number (3179175300).

Almost surely, 2^21043112005 is an apocalyptic number.

It is an amenable number.

21043112005 is a deficient number, since it is larger than the sum of its proper divisors (4390290395).

21043112005 is a wasteful number, since it uses less digits than its factorization.

21043112005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30278003.

The product of its (nonzero) digits is 240, while the sum is 19.

Adding to 21043112005 its reverse (50021134012), we get a palindrome (71064246017).

The spelling of 21043112005 in words is "twenty-one billion, forty-three million, one hundred twelve thousand, five".