21203410242 has 192 divisors, whose sum is σ = 53613342720. Its totient is φ = 5553160704.

The previous prime is 21203410201. The next prime is 21203410247. The reversal of 21203410242 is 24201430212.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (21203410247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 32771563 + ... + 32772209.

It is an arithmetic number, because the mean of its divisors is an integer number (279236160).

Almost surely, 2^21203410242 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21203410242, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26806671360).

21203410242 is an abundant number, since it is smaller than the sum of its proper divisors (32409932478).

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

21203410242 is a wasteful number, since it uses less digits than its factorization.

21203410242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 845 (or 838 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 21.

Adding to 21203410242 its reverse (24201430212), we get a palindrome (45404840454).

The spelling of 21203410242 in words is "twenty-one billion, two hundred three million, four hundred ten thousand, two hundred forty-two".