21163543 has 2 divisors, whose sum is σ = 21163544. Its totient is φ = 21163542.

The previous prime is 21163531. The next prime is 21163553. The reversal of 21163543 is 34536112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21163543 - 2¹⁷ = 21032471 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21163553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10581771 + 10581772.

It is an arithmetic number, because the mean of its divisors is an integer number (10581772).

Almost surely, 2^21163543 is an apocalyptic number.

21163543 is a deficient number, since it is larger than the sum of its proper divisors (1).

21163543 is an equidigital number, since it uses as much as digits as its factorization.

21163543 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2160, while the sum is 25.

The square root of 21163543 is about 4600.3850925765. The cubic root of 21163543 is about 276.6067612755.

Adding to 21163543 its reverse (34536112), we get a palindrome (55699655).

The spelling of 21163543 in words is "twenty-one million, one hundred sixty-three thousand, five hundred forty-three".