21005443124343 has 24 divisors (see below), whose sum is σ = 31721146685280. Its totient is φ = 13369065515520.

The previous prime is 21005443124329. The next prime is 21005443124357. The reversal of 21005443124343 is 34342134450012.

21005443124343 is a `hidden beast` number, since 2 + 1 + 0 + 0 + 544 + 31 + 2 + 43 + 43 = 666.

It is an interprime number because it is at equal distance from previous prime (21005443124329) and next prime (21005443124357).

It is not a de Polignac number, because 21005443124343 - 2¹⁰ = 21005443123319 is a prime.

It is a super-2 number, since 2×21005443124343² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21005443124298 and 21005443124307.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21005443124363) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 97277538 + ... + 97493231.

It is an arithmetic number, because the mean of its divisors is an integer number (1321714445220).

Almost surely, 2^{21005443124343} is an apocalyptic number.

21005443124343 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21005443124343 is a deficient number, since it is larger than the sum of its proper divisors (10715703560937).

21005443124343 is a wasteful number, since it uses less digits than its factorization.

21005443124343 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194771319 (or 194771316 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 36.

Adding to 21005443124343 its reverse (34342134450012), we get a palindrome (55347577574355).

The spelling of 21005443124343 in words is "twenty-one trillion, five billion, four hundred forty-three million, one hundred twenty-four thousand, three hundred forty-three".