21051343 has 2 divisors, whose sum is σ = 21051344. Its totient is φ = 21051342.

The previous prime is 21051341. The next prime is 21051353. The reversal of 21051343 is 34315012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21051343 - 2¹ = 21051341 is a prime.

Together with 21051341, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21051343.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21051341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10525671 + 10525672.

It is an arithmetic number, because the mean of its divisors is an integer number (10525672).

Almost surely, 2^21051343 is an apocalyptic number.

21051343 is a deficient number, since it is larger than the sum of its proper divisors (1).

21051343 is an equidigital number, since it uses as much as digits as its factorization.

21051343 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 21051343 is about 4588.1742556272. The cubic root of 21051343 is about 276.1170782081.

Adding to 21051343 its reverse (34315012), we get a palindrome (55366355).

The spelling of 21051343 in words is "twenty-one million, fifty-one thousand, three hundred forty-three".