21304404042 has 16 divisors (see below), whose sum is σ = 42610279392. Its totient is φ = 7101222800.

The previous prime is 21304404001. The next prime is 21304404049. The reversal of 21304404042 is 24040440312.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21304404049) 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 7 ways as a sum of consecutive naturals, for example, 243553 + ... + 319259.

It is an arithmetic number, because the mean of its divisors is an integer number (2663142462).

Almost surely, 2^21304404042 is an apocalyptic number.

21304404042 is an abundant number, since it is smaller than the sum of its proper divisors (21305875350).

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

21304404042 is a wasteful number, since it uses less digits than its factorization.

21304404042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122613.

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

Adding to 21304404042 its reverse (24040440312), we get a palindrome (45344844354).

The spelling of 21304404042 in words is "twenty-one billion, three hundred four million, four hundred four thousand, forty-two".