20543439 has 16 divisors (see below), whose sum is σ = 32666112. Its totient is φ = 11228448.

The previous prime is 20543431. The next prime is 20543443. The reversal of 20543439 is 93434502.

It is not a de Polignac number, because 20543439 - 2³ = 20543431 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20543431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20784 + ... + 21749.

It is an arithmetic number, because the mean of its divisors is an integer number (2041632).

Almost surely, 2^20543439 is an apocalyptic number.

20543439 is a deficient number, since it is larger than the sum of its proper divisors (12122673).

20543439 is a wasteful number, since it uses less digits than its factorization.

20543439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42566.

The product of its (nonzero) digits is 12960, while the sum is 30.

The square root of 20543439 is about 4532.4870656186. The cubic root of 20543439 is about 273.8783581032.

The spelling of 20543439 in words is "twenty million, five hundred forty-three thousand, four hundred thirty-nine".