20785543 has 4 divisors (see below), whose sum is σ = 22008240. Its totient is φ = 19562848.

The previous prime is 20785529. The next prime is 20785573. The reversal of 20785543 is 34558702.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 20785543 - 2⁵ = 20785511 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20785499 and 20785508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20785573) 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, 611323 + ... + 611356.

It is an arithmetic number, because the mean of its divisors is an integer number (5502060).

Almost surely, 2^20785543 is an apocalyptic number.

20785543 is a deficient number, since it is larger than the sum of its proper divisors (1222697).

20785543 is a wasteful number, since it uses less digits than its factorization.

20785543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1222696.

The product of its (nonzero) digits is 33600, while the sum is 34.

The square root of 20785543 is about 4559.1164714229. The cubic root of 20785543 is about 274.9500427158.

The spelling of 20785543 in words is "twenty million, seven hundred eighty-five thousand, five hundred forty-three".