21424743643 has 16 divisors (see below), whose sum is σ = 22213499616. Its totient is φ = 20649749760.

The previous prime is 21424743611. The next prime is 21424743649. The reversal of 21424743643 is 34634742412.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21424743643 - 2⁵ = 21424743611 is a prime.

It is a super-2 number, since 2×21424743643² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21424743596 and 21424743605.

It is not an unprimeable number, because it can be changed into a prime (21424743649) 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 15 ways as a sum of consecutive naturals, for example, 1629805 + ... + 1642897.

It is an arithmetic number, because the mean of its divisors is an integer number (1388343726).

Almost surely, 2^21424743643 is an apocalyptic number.

21424743643 is a deficient number, since it is larger than the sum of its proper divisors (788755973).

21424743643 is a wasteful number, since it uses less digits than its factorization.

21424743643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13614.

The product of its digits is 387072, while the sum is 40.

The spelling of 21424743643 in words is "twenty-one billion, four hundred twenty-four million, seven hundred forty-three thousand, six hundred forty-three".