21042212443 has 6 divisors (see below), whose sum is σ = 24477675756. Its totient is φ = 18036182052.

The previous prime is 21042212407. The next prime is 21042212449. The reversal of 21042212443 is 34421224012.

It is not a de Polignac number, because 21042212443 - 2²⁹ = 20505341531 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21042212449) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 214716405 + ... + 214716502.

It is an arithmetic number, because the mean of its divisors is an integer number (4079612626).

Almost surely, 2^21042212443 is an apocalyptic number.

21042212443 is a deficient number, since it is larger than the sum of its proper divisors (3435463313).

21042212443 is an equidigital number, since it uses as much as digits as its factorization.

21042212443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 429432921 (or 429432914 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 25.

Adding to 21042212443 its reverse (34421224012), we get a palindrome (55463436455).

The spelling of 21042212443 in words is "twenty-one billion, forty-two million, two hundred twelve thousand, four hundred forty-three".