21342134431 has 4 divisors (see below), whose sum is σ = 21342453664. Its totient is φ = 21341815200.

The previous prime is 21342134417. The next prime is 21342134483. The reversal of 21342134431 is 13443124312.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21342134431 is a prime.

It is a super-2 number, since 2×21342134431² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21342134431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21342134531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16650 + ... + 207271.

It is an arithmetic number, because the mean of its divisors is an integer number (5335613416).

Almost surely, 2^21342134431 is an apocalyptic number.

21342134431 is a deficient number, since it is larger than the sum of its proper divisors (319233).

21342134431 is an equidigital number, since it uses as much as digits as its factorization.

21342134431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319232.

The product of its digits is 6912, while the sum is 28.

Adding to 21342134431 its reverse (13443124312), we get a palindrome (34785258743).

The spelling of 21342134431 in words is "twenty-one billion, three hundred forty-two million, one hundred thirty-four thousand, four hundred thirty-one".