21103244443 has 4 divisors (see below), whose sum is σ = 21103691400. Its totient is φ = 21102797488.

The previous prime is 21103244363. The next prime is 21103244453. The reversal of 21103244443 is 34444230112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21103244443 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21103244453) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 142993 + ... + 250306.

It is an arithmetic number, because the mean of its divisors is an integer number (5275922850).

Almost surely, 2^21103244443 is an apocalyptic number.

21103244443 is a deficient number, since it is larger than the sum of its proper divisors (446957).

21103244443 is an equidigital number, since it uses as much as digits as its factorization.

21103244443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 446956.

The product of its (nonzero) digits is 9216, while the sum is 28.

Adding to 21103244443 its reverse (34444230112), we get a palindrome (55547474555).

The spelling of 21103244443 in words is "twenty-one billion, one hundred three million, two hundred forty-four thousand, four hundred forty-three".