21110242443 has 4 divisors (see below), whose sum is σ = 28146989928. Its totient is φ = 14073494960.

The previous prime is 21110242409. The next prime is 21110242469. The reversal of 21110242443 is 34424201112.

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

It is a cyclic number.

It is not a de Polignac number, because 21110242443 - 2⁹ = 21110241931 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21110242403) by changing a digit.

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, 3518373738 + ... + 3518373743.

It is an arithmetic number, because the mean of its divisors is an integer number (7036747482).

Almost surely, 2^21110242443 is an apocalyptic number.

21110242443 is a deficient number, since it is larger than the sum of its proper divisors (7036747485).

21110242443 is an equidigital number, since it uses as much as digits as its factorization.

21110242443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7036747484.

The product of its (nonzero) digits is 1536, while the sum is 24.

Adding to 21110242443 its reverse (34424201112), we get a palindrome (55534443555).

The spelling of 21110242443 in words is "twenty-one billion, one hundred ten million, two hundred forty-two thousand, four hundred forty-three".