20785489 has 4 divisors (see below), whose sum is σ = 21502260. Its totient is φ = 20068720.

The previous prime is 20785447. The next prime is 20785493. The reversal of 20785489 is 98458702.

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 9000000 + 11785489 = 3000^2 + 3433^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20785489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20785409) 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, 358342 + ... + 358399.

It is an arithmetic number, because the mean of its divisors is an integer number (5375565).

Almost surely, 2^20785489 is an apocalyptic number.

20785489 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

20785489 is a deficient number, since it is larger than the sum of its proper divisors (716771).

20785489 is an equidigital number, since it uses as much as digits as its factorization.

20785489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 716770.

The product of its (nonzero) digits is 161280, while the sum is 43.

The square root of 20785489 is about 4559.1105492190. The cubic root of 20785489 is about 274.9498046126.

The spelling of 20785489 in words is "twenty million, seven hundred eighty-five thousand, four hundred eighty-nine".