20784089 has 4 divisors (see below), whose sum is σ = 21291060. Its totient is φ = 20277120.

The previous prime is 20784077. The next prime is 20784143. The reversal of 20784089 is 98048702.

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

It can be written as a sum of positive squares in 2 ways, for example, as 4243600 + 16540489 = 2060^2 + 4067^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20784089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20784389) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 253424 + ... + 253505.

It is an arithmetic number, because the mean of its divisors is an integer number (5322765).

Almost surely, 2^20784089 is an apocalyptic number.

It is an amenable number.

20784089 is a deficient number, since it is larger than the sum of its proper divisors (506971).

20784089 is an equidigital number, since it uses as much as digits as its factorization.

20784089 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 506970.

The product of its (nonzero) digits is 32256, while the sum is 38.

The square root of 20784089 is about 4558.9570079131. The cubic root of 20784089 is about 274.9436314218.

The spelling of 20784089 in words is "twenty million, seven hundred eighty-four thousand, eighty-nine".