21311444424 has 16 divisors (see below), whose sum is σ = 53278611120. Its totient is φ = 7103814800.

The previous prime is 21311444383. The next prime is 21311444431. The reversal of 21311444424 is 42444411312.

It is a happy number.

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21311444391 and 21311444400.

It is an unprimeable number.

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, 443988402 + ... + 443988449.

It is an arithmetic number, because the mean of its divisors is an integer number (3329913195).

Almost surely, 2^21311444424 is an apocalyptic number.

21311444424 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21311444424 is an abundant number, since it is smaller than the sum of its proper divisors (31967166696).

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

21311444424 is a wasteful number, since it uses less digits than its factorization.

21311444424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 887976860 (or 887976856 counting only the distinct ones).

The product of its digits is 12288, while the sum is 30.

Adding to 21311444424 its reverse (42444411312), we get a palindrome (63755855736).

The spelling of 21311444424 in words is "twenty-one billion, three hundred eleven million, four hundred forty-four thousand, four hundred twenty-four".