21134344431 has 4 divisors (see below), whose sum is σ = 28179125912. Its totient is φ = 14089562952.

The previous prime is 21134344421. The next prime is 21134344513. The reversal of 21134344431 is 13444343112.

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

It is not a de Polignac number, because 21134344431 - 2⁶ = 21134344367 is a prime.

It is a super-2 number, since 2×21134344431² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21134344421) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 3522390736 + ... + 3522390741.

It is an arithmetic number, because the mean of its divisors is an integer number (7044781478).

Almost surely, 2^21134344431 is an apocalyptic number.

21134344431 is a deficient number, since it is larger than the sum of its proper divisors (7044781481).

21134344431 is an equidigital number, since it uses as much as digits as its factorization.

21134344431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7044781480.

The product of its digits is 13824, while the sum is 30.

Adding to 21134344431 its reverse (13444343112), we get a palindrome (34578687543).

The spelling of 21134344431 in words is "twenty-one billion, one hundred thirty-four million, three hundred forty-four thousand, four hundred thirty-one".