21131431212442 has 16 divisors (see below), whose sum is σ = 32216963489064. Its totient is φ = 10392445440000.

The previous prime is 21131431212371. The next prime is 21131431212467. The reversal of 21131431212442 is 24421213413112.

It can be written as a sum of positive squares in 4 ways, for example, as 20388647513641 + 742783698801 = 4515379^2 + 861849^2 .

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, 25475442 + ... + 26291842.

Almost surely, 2^{21131431212442} is an apocalyptic number.

21131431212442 is a deficient number, since it is larger than the sum of its proper divisors (11085532276622).

21131431212442 is a wasteful number, since it uses less digits than its factorization.

21131431212442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1028625.

The product of its digits is 9216, while the sum is 31.

Adding to 21131431212442 its reverse (24421213413112), we get a palindrome (45552644625554).

The spelling of 21131431212442 in words is "twenty-one trillion, one hundred thirty-one billion, four hundred thirty-one million, two hundred twelve thousand, four hundred forty-two".