21203424242 has 64 divisors (see below), whose sum is σ = 43612176384. Its totient is φ = 7463327040.

The previous prime is 21203424241. The next prime is 21203424247. The reversal of 21203424242 is 24242430212.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is not an unprimeable number, because it can be changed into a prime (21203424241) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18578 + ... + 206765.

It is an arithmetic number, because the mean of its divisors is an integer number (681440256).

Almost surely, 2^21203424242 is an apocalyptic number.

21203424242 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21203424242 is an abundant number, since it is smaller than the sum of its proper divisors (22408752142).

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

21203424242 is a wasteful number, since it uses less digits than its factorization.

21203424242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 225423.

The product of its (nonzero) digits is 6144, while the sum is 26.

Adding to 21203424242 its reverse (24242430212), we get a palindrome (45445854454).

The spelling of 21203424242 in words is "twenty-one billion, two hundred three million, four hundred twenty-four thousand, two hundred forty-two".