21002112443 has 16 divisors (see below), whose sum is σ = 23962034880. Its totient is φ = 18235570176.

The previous prime is 21002112437. The next prime is 21002112449. The reversal of 21002112443 is 34421120012.

It is an interprime number because it is at equal distance from previous prime (21002112437) and next prime (21002112449).

It is a cyclic number.

It is not a de Polignac number, because 21002112443 - 2¹⁰ = 21002111419 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21002112449) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 365978 + ... + 419456.

It is an arithmetic number, because the mean of its divisors is an integer number (1497627180).

Almost surely, 2^21002112443 is an apocalyptic number.

21002112443 is a deficient number, since it is larger than the sum of its proper divisors (2959922437).

21002112443 is a wasteful number, since it uses less digits than its factorization.

21002112443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55286.

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 21002112443 its reverse (34421120012), we get a palindrome (55423232455).

The spelling of 21002112443 in words is "twenty-one billion, two million, one hundred twelve thousand, four hundred forty-three".