20205543 has 4 divisors (see below), whose sum is σ = 26940728. Its totient is φ = 13470360.

The previous prime is 20205541. The next prime is 20205551. The reversal of 20205543 is 34550202.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20205543 - 2¹ = 20205541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20205541) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3367588 + ... + 3367593.

It is an arithmetic number, because the mean of its divisors is an integer number (6735182).

Almost surely, 2^20205543 is an apocalyptic number.

20205543 is a deficient number, since it is larger than the sum of its proper divisors (6735185).

20205543 is an equidigital number, since it uses as much as digits as its factorization.

20205543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6735184.

The product of its (nonzero) digits is 1200, while the sum is 21.

The square root of 20205543 is about 4495.0576192080. The cubic root of 20205543 is about 272.3684767763.

Adding to 20205543 its reverse (34550202), we get a palindrome (54755745).

The spelling of 20205543 in words is "twenty million, two hundred five thousand, five hundred forty-three".