21204430242 has 16 divisors (see below), whose sum is σ = 44903499552. Its totient is φ = 6652370240.

The previous prime is 21204430241. The next prime is 21204430267. The reversal of 21204430242 is 24203440212.

It is not an unprimeable number, because it can be changed into a prime (21204430241) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 103943184 + ... + 103943387.

It is an arithmetic number, because the mean of its divisors is an integer number (2806468722).

Almost surely, 2^21204430242 is an apocalyptic number.

21204430242 is an abundant number, since it is smaller than the sum of its proper divisors (23699069310).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21204430242 is a wasteful number, since it uses less digits than its factorization.

21204430242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207886593.

The product of its (nonzero) digits is 3072, while the sum is 24.

Adding to 21204430242 its reverse (24203440212), we get a palindrome (45407870454).

The spelling of 21204430242 in words is "twenty-one billion, two hundred four million, four hundred thirty thousand, two hundred forty-two".