20158543 has 4 divisors (see below), whose sum is σ = 20188408. Its totient is φ = 20128680.

The previous prime is 20158519. The next prime is 20158547. The reversal of 20158543 is 34585102.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20158543 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 (20158547) 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 in 3 ways as a sum of consecutive naturals, for example, 13896 + ... + 15277.

It is an arithmetic number, because the mean of its divisors is an integer number (5047102).

Almost surely, 2^20158543 is an apocalyptic number.

20158543 is a deficient number, since it is larger than the sum of its proper divisors (29865).

20158543 is an equidigital number, since it uses as much as digits as its factorization.

20158543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29864.

The product of its (nonzero) digits is 4800, while the sum is 28.

The square root of 20158543 is about 4489.8266113515. The cubic root of 20158543 is about 272.1571278914.

The spelling of 20158543 in words is "twenty million, one hundred fifty-eight thousand, five hundred forty-three".