21131312442 has 32 divisors (see below), whose sum is σ = 43002567360. Its totient is φ = 6920578560.

The previous prime is 21131312431. The next prime is 21131312473. The reversal of 21131312442 is 24421313112.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 668842 + ... + 699722.

It is an arithmetic number, because the mean of its divisors is an integer number (1343830230).

Almost surely, 2^21131312442 is an apocalyptic number.

21131312442 is an abundant number, since it is smaller than the sum of its proper divisors (21871254918).

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

21131312442 is a wasteful number, since it uses less digits than its factorization.

21131312442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32878.

The product of its digits is 1152, while the sum is 24.

Adding to 21131312442 its reverse (24421313112), we get a palindrome (45552625554).

The spelling of 21131312442 in words is "twenty-one billion, one hundred thirty-one million, three hundred twelve thousand, four hundred forty-two".