21356433430242 has 16 divisors (see below), whose sum is σ = 44960912484960. Its totient is φ = 6744136872672.

The previous prime is 21356433430231. The next prime is 21356433430259. The reversal of 21356433430242 is 24203433465312.

It is a junction number, because it is equal to n+sod(n) for n = 21356433430194 and 21356433430203.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 93668567563 + ... + 93668567790.

It is an arithmetic number, because the mean of its divisors is an integer number (2810057030310).

Almost surely, 2^{21356433430242} is an apocalyptic number.

21356433430242 is an abundant number, since it is smaller than the sum of its proper divisors (23604479054718).

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

21356433430242 is a wasteful number, since it uses less digits than its factorization.

21356433430242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187337135377.

The product of its (nonzero) digits is 1244160, while the sum is 42.

Adding to 21356433430242 its reverse (24203433465312), we get a palindrome (45559866895554).

The spelling of 21356433430242 in words is "twenty-one trillion, three hundred fifty-six billion, four hundred thirty-three million, four hundred thirty thousand, two hundred forty-two".