20785243 has 4 divisors (see below), whose sum is σ = 20820888. Its totient is φ = 20749600.

The previous prime is 20785241. The next prime is 20785253. The reversal of 20785243 is 34258702.

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 20785243 - 2¹ = 20785241 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a zygodrome in base 3.

It is not an unprimeable number, because it can be changed into a prime (20785241) 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, 16933 + ... + 18118.

It is an arithmetic number, because the mean of its divisors is an integer number (5205222).

Almost surely, 2^20785243 is an apocalyptic number.

20785243 is a deficient number, since it is larger than the sum of its proper divisors (35645).

20785243 is an equidigital number, since it uses as much as digits as its factorization.

20785243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35644.

The product of its (nonzero) digits is 13440, while the sum is 31.

The square root of 20785243 is about 4559.0835701926. The cubic root of 20785243 is about 274.9487199148.

The spelling of 20785243 in words is "twenty million, seven hundred eighty-five thousand, two hundred forty-three".