20403543 has 16 divisors (see below), whose sum is σ = 27986816. Its totient is φ = 13214880.

The previous prime is 20403541. The next prime is 20403589. The reversal of 20403543 is 34530402.

It is a happy number.

It is not a de Polignac number, because 20403543 - 2¹ = 20403541 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 (20403541) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35448 + ... + 36018.

It is an arithmetic number, because the mean of its divisors is an integer number (1749176).

Almost surely, 2^20403543 is an apocalyptic number.

20403543 is a deficient number, since it is larger than the sum of its proper divisors (7583273).

20403543 is a wasteful number, since it uses less digits than its factorization.

20403543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 894.

The product of its (nonzero) digits is 1440, while the sum is 21.

The square root of 20403543 is about 4517.0281159187. The cubic root of 20403543 is about 273.2552591144.

Adding to 20403543 its reverse (34530402), we get a palindrome (54933945).

The spelling of 20403543 in words is "twenty million, four hundred three thousand, five hundred forty-three".