21385371210042 has 128 divisors (see below), whose sum is σ = 50682082222080. Its totient is φ = 5888973404160.

The previous prime is 21385371210031. The next prime is 21385371210067. The reversal of 21385371210042 is 24001217358312.

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 63 ways as a sum of consecutive naturals, for example, 444495084 + ... + 444543192.

It is an arithmetic number, because the mean of its divisors is an integer number (395953767360).

Almost surely, 2^{21385371210042} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21385371210042, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25341041111040).

21385371210042 is an abundant number, since it is smaller than the sum of its proper divisors (29296711012038).

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

21385371210042 is a wasteful number, since it uses less digits than its factorization.

21385371210042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51596.

The product of its (nonzero) digits is 80640, while the sum is 39.

Adding to 21385371210042 its reverse (24001217358312), we get a palindrome (45386588568354).

The spelling of 21385371210042 in words is "twenty-one trillion, three hundred eighty-five billion, three hundred seventy-one million, two hundred ten thousand, forty-two".