21105243343 has 2 divisors, whose sum is σ = 21105243344. Its totient is φ = 21105243342.

The previous prime is 21105243323. The next prime is 21105243349. The reversal of 21105243343 is 34334250112.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21105243343 - 2²¹ = 21103146191 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21105243349) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10552621671 + 10552621672.

It is an arithmetic number, because the mean of its divisors is an integer number (10552621672).

Almost surely, 2^21105243343 is an apocalyptic number.

21105243343 is a deficient number, since it is larger than the sum of its proper divisors (1).

21105243343 is an equidigital number, since it uses as much as digits as its factorization.

21105243343 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 28.

Adding to 21105243343 its reverse (34334250112), we get a palindrome (55439493455).

The spelling of 21105243343 in words is "twenty-one billion, one hundred five million, two hundred forty-three thousand, three hundred forty-three".